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  • MySQL Datefields: duplicate or calculate?

    - by Konerak
    We are using a table with a structure imposed upon us more than 10 years ago. We are allowed to add columns, but urged not to change existing columns. Certain columns are meant to represent dates, but are put in different format. Amongst others: * CHAR(6): YYMMDD * CHAR(6): DDMMYY * CHAR(8): YYYYMMDD * CHAR(8): DDMMYYYY * DATE * DATETIME Since we now would like to do some more complex queries, using advanced date functions, my manager proposed to d*uplicate those problem columns* to a proper FORMATTED_OLDCOLUMNNAME column using a DATE or DATETIME format. Is this the way to go? Couldn't we just use the STR_TO_DATE function each time we accessed the columns? To avoid every query having to copy-paste the function, I could still work with a view or a stored procedure, but duplicating data to avoid recalculation sounds wrong. Solutions I see (I guess I prefer 2.2.1) 1. Physically duplicate columns 1.1 In the same table 1.1.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.1.2 Maintained by a trigger on each modification 1.2 In a separate table 1.2.1 Added by each script that does a modification (INSERT/UPDATE/REPLACE/...) 1.2.2 Maintained by a trigger on each modification 2. On-demand transformation 2.1 Each query has to perform the transformation 2.1.1 Using copy-paste in the source code 2.1.2 Using a library 2.1.3 Using a STORED PROCEDURE 2.2 A view performs the transformation 2.2.1 A separate table replacing the entire table 2.2.2 A separate table just adding the date-fields for the primary keys Am I right to say it's better to recalculate than to store? And would a view be a good solution?

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  • SQL SERVER – Tricks to Replace SELECT * with Column Names – SQL in Sixty Seconds #017 – Video

    - by pinaldave
    You might have heard many times that one should not use SELECT * as there are many disadvantages to the usage of the SELECT *. I also believe that there are always rare occasion when we need every single column of the query. In most of the cases, we only need a few columns of the query and we should retrieve only those columns. SELECT * has many disadvantages. Let me list a few and remaining you can add as a comment.  Retrieves unnecessary columns and increases network traffic When a new columns are added views needs to be refreshed manually Leads to usage of sub-optimal execution plan Uses clustered index in most of the cases instead of using optimal index It is difficult to debug. There are two quick tricks I have discussed in the video which explains how users can avoid using SELECT * but instead list the column names. 1) Drag the columns folder from SQL Server Management Studio to Query Editor 2) Right Click on Table Name >> Script TAble AS >> SELECT To… >> Select option It is extremely easy to list the column names in the table. In today’s sixty seconds video, you will notice that I was able to demonstrate both the methods very quickly. From now onwards there should be no excuse for not listing ColumnName. Let me ask a question back – is there ever a reason to SELECT *? If yes, would you please share that as a comment. More on SELECT *: SQL SERVER – Solution – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – SELECT vs. SET Performance Comparison I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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  • July, the 31 Days of SQL Server DMO’s – Day 21 (sys.dm_db_partition_stats)

    - by Tamarick Hill
    The sys.dm_db_partition_stats DMV returns page count and row count information for each table or index within your database. Lets have a quick look at this DMV so we can review some of the results. **NOTE: I am going to create an ‘ObjectName’ column in our result set so that we can more easily identify tables. SELECT object_name(object_id) ObjectName, * FROM sys.dm_db_partition_stats As stated above, the first column in our result set is an Object name based on the object_id column of this result set. The partition_id column refers to the partition_id of the index in question. Each index will have at least 1 unique partition_id and will have more depending on if the object has been partitioned. The index_id column relates back to the sys.indexes table and uniquely identifies an index on a given object. A value of 0 (zero) in this column would indicate the object is a HEAP and a value of 1 (one) would signify the Clustered Index. Next is the partition_number which would signify the number of the partition for a particular object_id. Since none of my tables in my result set have been partitioned, they all display 1 for the partition_number. Next we have the in_row_data_page_count which tells us the number of data pages used to store in-row data for a given index. The in_row_used_page_count is the number of pages used to store and manage the in-row data. If we look at the first row in the result set, we will see we have 700 for this column and 680 for the previous. This means that just to manage the data (not store it) is requiring 20 pages. The next column in_row_reserved_page_count is how many pages have been reserved, regardless if they are being used or not. The next 2 columns are used for storing LOB (Large Object) data which could be text, image, varchar(max), or varbinary(max) columns. The next two columns, row_overflow, represent pages used for data that exceed the 8,060 byte row size limit for the in-row data pages. The next columns used_page_count and reserved_page_count represent the sum of the in_row, lob, and row_overflow columns discussed earlier. Lastly is a row_count column which displays the number of rows that are in a particular index. This DMV is a very powerful resource for identifying page and row count information. By knowing the page counts for indexes within your database, you are able to easily calculate the size of indexes. For more information on this DMV, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms187737.aspx Follow me on Twitter @PrimeTimeDBA

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  • July, the 31 Days of SQL Server DMO’s – Day 24 (sys.dm_db_index_operational_stats)

    - by Tamarick Hill
    The sys.dm_db_index_operational_stats Dynamic Management Function returns information about the IO, locking, and access methods for the indexes that you currently have on your SQL Server Instance. This function takes four input parameters which are (1) database_id, (2) object_id, (3) index_id, and (4) partition_number. Let’s have a look at the results from this function against our AdventureWorks2012 database. This function returns a ton of columns, so not only will I not attempt to describe each of the columns, I wont even attempt to display all of them here. My query below will give you a subset of the columns returned from this function. SELECT database_id, object_id, index_id, partition_number, leaf_insert_count, leaf_delete_count, leaf_update_count, leaf_ghost_count, nonleaf_insert_count, nonleaf_delete_count, nonleaf_update_count, range_scan_count, forwarded_fetch_count, row_lock_count, row_lock_wait_count, page_lock_count, page_lock_wait_count, Index_lock_promotion_attempt_count, index_lock_promotion_count, page_compression_attempt_count, page_compression_success_count FROM sys.dm_db_index_operational_stats(db_id('AdventureWorks2012'), NULL, NULL, NULL) The first four columns in the result set represent the values that we passed in as our input parameters. If you use NULL’s as I did, then you will see results for every index on your system. I specified a database_id so my result set only shows those records pertaining to my AdventureWorks2012 database. The next columns in the result set provide you with information on how may inserts, deletes, or updates that have taken place on your leaf and nonleaf index levels. The nonleaf levels would refer to the intermediate and root index levels. In the middle of these you see a leaf_ghost_count column, which represents the number of records that have been logically deleted and marked as “ghosted”  and are waiting on the background ghost cleanup process to physically remove them. The range_scan_count column represents the number of range or table scans that have been performed against an index. The forwarded_fetch_count column represents the number of rows that were returned from a forwarding row pointer. The row_lock_count and row_lock_wait_count represent the number of row locks that have been requested for an index and the number of times SQL has had to wait on a row lock respectively. The page_lock_count and page_lock_wait_count represent the number of page locks that have been requested for an index and the number of times SQL has had to wait on a page lock respectively. The index_lock_promotion_attempt_count represents the number of times the database engine has attempted to promote a lock to the index level. The index_lock_promotion_count column displays how many times that index lock promotion was successful. Lastly the page_compression_attempt_count and page_compression_success_count represents how many times a page was attempted to be compressed and how many times the attempt was successful. As you can see there is a ton of information returned from this DMV. The DMV we reviewed on yesterday (sys.dm_db_index_usage_stats) provided you with good information on when and how indexes have been used, but this DMF takes an even deeper dive into these statistics. If you are interested in performing a very detailed analysis on the operational stats of your indexes, this is not only a good place to start, but more than likely the best place. For more information on this Dynamic Management Function, please see the below Books Online link: http://msdn.microsoft.com/en-us/library/ms174281.aspx Follow me on Twitter @PrimeTimeDBA

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  • Sniffing out SQL Code Smells: Inconsistent use of Symbolic names and Datatypes

    - by Phil Factor
    It is an awkward feeling. You’ve just delivered a database application that seems to be working fine in production, and you just run a few checks on it. You discover that there is a potential bug that, out of sheer good chance, hasn’t kicked in to produce an error; but it lurks, like a smoking bomb. Worse, maybe you find that the bug has started its evil work of corrupting the data, but in ways that nobody has, so far detected. You investigate, and find the damage. You are somehow going to have to repair it. Yes, it still very occasionally happens to me. It is not a nice feeling, and I do anything I can to prevent it happening. That’s why I’m interested in SQL code smells. SQL Code Smells aren’t necessarily bad practices, but just show you where to focus your attention when checking an application. Sometimes with databases the bugs can be subtle. SQL is rather like HTML: the language does its best to try to carry out your wishes, rather than to be picky about your bugs. Most of the time, this is a great benefit, but not always. One particular place where this can be detrimental is where you have implicit conversion between different data types. Most of the time it is completely harmless but we’re  concerned about the occasional time it isn’t. Let’s give an example: String truncation. Let’s give another even more frightening one, rounding errors on assignment to a number of different precision. Each requires a blog-post to explain in detail and I’m not now going to try. Just remember that it is not always a good idea to assign data to variables, parameters or even columns when they aren’t the same datatype, especially if you are relying on implicit conversion to work its magic.For details of the problem and the consequences, see here:  SR0014: Data loss might occur when casting from {Type1} to {Type2} . For any experienced Database Developer, this is a more frightening read than a Vampire Story. This is why one of the SQL Code Smells that makes me edgy, in my own or other peoples’ code, is to see parameters, variables and columns that have the same names and different datatypes. Whereas quite a lot of this is perfectly normal and natural, you need to check in case one of two things have gone wrong. Either sloppy naming, or mixed datatypes. Sure it is hard to remember whether you decided that the length of a log entry was 80 or 100 characters long, or the precision of a number. That is why a little check like this I’m going to show you is excellent for tidying up your code before you check it back into source Control! 1/ Checking Parameters only If you were just going to check parameters, you might just do this. It simply groups all the parameters, either input or output, of all the routines (e.g. stored procedures or functions) by their name and checks to see, in the HAVING clause, whether their data types are all the same. If not, it lists all the examples and their origin (the routine) Even this little check can occasionally be scarily revealing. ;WITH userParameter AS  ( SELECT   c.NAME AS ParameterName,  OBJECT_SCHEMA_NAME(c.object_ID) + '.' + OBJECT_NAME(c.object_ID) AS ObjectName,  t.name + ' '     + CASE     --we may have to put in the length            WHEN t.name IN ('char', 'varchar', 'nchar', 'nvarchar')             THEN '('               + CASE WHEN c.max_length = -1 THEN 'MAX'                ELSE CONVERT(VARCHAR(4),                    CASE WHEN t.name IN ('nchar', 'nvarchar')                      THEN c.max_length / 2 ELSE c.max_length                    END)                END + ')'         WHEN t.name IN ('decimal', 'numeric')             THEN '(' + CONVERT(VARCHAR(4), c.precision)                   + ',' + CONVERT(VARCHAR(4), c.Scale) + ')'         ELSE ''      END  --we've done with putting in the length      + CASE WHEN XML_collection_ID <> 0         THEN --deal with object schema names             '(' + CASE WHEN is_XML_Document = 1                    THEN 'DOCUMENT '                    ELSE 'CONTENT '                   END              + COALESCE(               (SELECT QUOTENAME(ss.name) + '.' + QUOTENAME(sc.name)                FROM sys.xml_schema_collections sc                INNER JOIN Sys.Schemas ss ON sc.schema_ID = ss.schema_ID                WHERE sc.xml_collection_ID = c.XML_collection_ID),'NULL') + ')'          ELSE ''         END        AS [DataType]  FROM sys.parameters c  INNER JOIN sys.types t ON c.user_Type_ID = t.user_Type_ID  WHERE OBJECT_SCHEMA_NAME(c.object_ID) <> 'sys'   AND parameter_id>0)SELECT CONVERT(CHAR(80),objectName+'.'+ParameterName),DataType FROM UserParameterWHERE ParameterName IN   (SELECT ParameterName FROM UserParameter    GROUP BY ParameterName    HAVING MIN(Datatype)<>MAX(DataType))ORDER BY ParameterName   so, in a very small example here, we have a @ClosingDelimiter variable that is only CHAR(1) when, by the looks of it, it should be up to ten characters long, or even worse, a function that should be a char(1) and seems to let in a string of ten characters. Worth investigating. Then we have a @Comment variable that can't decide whether it is a VARCHAR(2000) or a VARCHAR(MAX) 2/ Columns and Parameters Actually, once we’ve cleared up the mess we’ve made of our parameter-naming in the database we’re inspecting, we’re going to be more interested in listing both columns and parameters. We can do this by modifying the routine to list columns as well as parameters. Because of the slight complexity of creating the string version of the datatypes, we will create a fake table of both columns and parameters so that they can both be processed the same way. After all, we want the datatypes to match Unfortunately, parameters do not expose all the attributes we are interested in, such as whether they are nullable (oh yes, subtle bugs happen if this isn’t consistent for a datatype). We’ll have to leave them out for this check. Voila! A slight modification of the first routine ;WITH userObject AS  ( SELECT   Name AS DataName,--the actual name of the parameter or column ('@' removed)  --and the qualified object name of the routine  OBJECT_SCHEMA_NAME(ObjectID) + '.' + OBJECT_NAME(ObjectID) AS ObjectName,  --now the harder bit: the definition of the datatype.  TypeName + ' '     + CASE     --we may have to put in the length. e.g. CHAR (10)           WHEN TypeName IN ('char', 'varchar', 'nchar', 'nvarchar')             THEN '('               + CASE WHEN MaxLength = -1 THEN 'MAX'                ELSE CONVERT(VARCHAR(4),                    CASE WHEN TypeName IN ('nchar', 'nvarchar')                      THEN MaxLength / 2 ELSE MaxLength                    END)                END + ')'         WHEN TypeName IN ('decimal', 'numeric')--a BCD number!             THEN '(' + CONVERT(VARCHAR(4), Precision)                   + ',' + CONVERT(VARCHAR(4), Scale) + ')'         ELSE ''      END  --we've done with putting in the length      + CASE WHEN XML_collection_ID <> 0 --tush tush. XML         THEN --deal with object schema names             '(' + CASE WHEN is_XML_Document = 1                    THEN 'DOCUMENT '                    ELSE 'CONTENT '                   END              + COALESCE(               (SELECT TOP 1 QUOTENAME(ss.name) + '.' + QUOTENAME(sc.Name)                FROM sys.xml_schema_collections sc                INNER JOIN Sys.Schemas ss ON sc.schema_ID = ss.schema_ID                WHERE sc.xml_collection_ID = XML_collection_ID),'NULL') + ')'          ELSE ''         END        AS [DataType],       DataObjectType  FROM   (Select t.name AS TypeName, REPLACE(c.name,'@','') AS Name,          c.max_length AS MaxLength, c.precision AS [Precision],           c.scale AS [Scale], c.[Object_id] AS ObjectID, XML_collection_ID,          is_XML_Document,'P' AS DataobjectType  FROM sys.parameters c  INNER JOIN sys.types t ON c.user_Type_ID = t.user_Type_ID  AND parameter_id>0  UNION all  Select t.name AS TypeName, c.name AS Name, c.max_length AS MaxLength,          c.precision AS [Precision], c.scale AS [Scale],          c.[Object_id] AS ObjectID, XML_collection_ID,is_XML_Document,          'C' AS DataobjectType            FROM sys.columns c  INNER JOIN sys.types t ON c.user_Type_ID = t.user_Type_ID   WHERE OBJECT_SCHEMA_NAME(c.object_ID) <> 'sys'  )f)SELECT CONVERT(CHAR(80),objectName+'.'   + CASE WHEN DataobjectType ='P' THEN '@' ELSE '' END + DataName),DataType FROM UserObjectWHERE DataName IN   (SELECT DataName FROM UserObject   GROUP BY DataName    HAVING MIN(Datatype)<>MAX(DataType))ORDER BY DataName     Hmm. I can tell you I found quite a few minor issues with the various tabases I tested this on, and found some potential bugs that really leap out at you from the results. Here is the start of the result for AdventureWorks. Yes, AccountNumber is, for some reason, a Varchar(10) in the Customer table. Hmm. odd. Why is a city fifty characters long in that view?  The idea of the description of a colour being 256 characters long seems over-ambitious. Go down the list and you'll spot other mistakes. There are no bugs, but just mess. We started out with a listing to examine parameters, then we mixed parameters and columns. Our last listing is for a slightly more in-depth look at table columns. You’ll notice that we’ve delibarately removed the indication of whether a column is persisted, or is an identity column because that gives us false positives for our code smells. If you just want to browse your metadata for other reasons (and it can quite help in some circumstances) then uncomment them! ;WITH userColumns AS  ( SELECT   c.NAME AS columnName,  OBJECT_SCHEMA_NAME(c.object_ID) + '.' + OBJECT_NAME(c.object_ID) AS ObjectName,  REPLACE(t.name + ' '   + CASE WHEN is_computed = 1 THEN ' AS ' + --do DDL for a computed column          (SELECT definition FROM sys.computed_columns cc           WHERE cc.object_id = c.object_id AND cc.column_ID = c.column_ID)     --we may have to put in the length            WHEN t.Name IN ('char', 'varchar', 'nchar', 'nvarchar')             THEN '('               + CASE WHEN c.Max_Length = -1 THEN 'MAX'                ELSE CONVERT(VARCHAR(4),                    CASE WHEN t.Name IN ('nchar', 'nvarchar')                      THEN c.Max_Length / 2 ELSE c.Max_Length                    END)                END + ')'       WHEN t.name IN ('decimal', 'numeric')       THEN '(' + CONVERT(VARCHAR(4), c.precision) + ',' + CONVERT(VARCHAR(4), c.Scale) + ')'       ELSE ''      END + CASE WHEN c.is_rowguidcol = 1          THEN ' ROWGUIDCOL'          ELSE ''         END + CASE WHEN XML_collection_ID <> 0            THEN --deal with object schema names             '(' + CASE WHEN is_XML_Document = 1                THEN 'DOCUMENT '                ELSE 'CONTENT '               END + COALESCE((SELECT                QUOTENAME(ss.name) + '.' + QUOTENAME(sc.name)                FROM                sys.xml_schema_collections sc                INNER JOIN Sys.Schemas ss ON sc.schema_ID = ss.schema_ID                WHERE                sc.xml_collection_ID = c.XML_collection_ID),                'NULL') + ')'            ELSE ''           END + CASE WHEN is_identity = 1             THEN CASE WHEN OBJECTPROPERTY(object_id,                'IsUserTable') = 1 AND COLUMNPROPERTY(object_id,                c.name,                'IsIDNotForRepl') = 0 AND OBJECTPROPERTY(object_id,                'IsMSShipped') = 0                THEN ''                ELSE ' NOT FOR REPLICATION '               END             ELSE ''            END + CASE WHEN c.is_nullable = 0               THEN ' NOT NULL'               ELSE ' NULL'              END + CASE                WHEN c.default_object_id <> 0                THEN ' DEFAULT ' + object_Definition(c.default_object_id)                ELSE ''               END + CASE                WHEN c.collation_name IS NULL                THEN ''                WHEN c.collation_name <> (SELECT                collation_name                FROM                sys.databases                WHERE                name = DB_NAME()) COLLATE Latin1_General_CI_AS                THEN COALESCE(' COLLATE ' + c.collation_name,                '')                ELSE ''                END,'  ',' ') AS [DataType]FROM sys.columns c  INNER JOIN sys.types t ON c.user_Type_ID = t.user_Type_ID  WHERE OBJECT_SCHEMA_NAME(c.object_ID) <> 'sys')SELECT CONVERT(CHAR(80),objectName+'.'+columnName),DataType FROM UserColumnsWHERE columnName IN (SELECT columnName FROM UserColumns  GROUP BY columnName  HAVING MIN(Datatype)<>MAX(DataType))ORDER BY columnName If you take a look down the results against Adventureworks, you'll see once again that there are things to investigate, mostly, in the illustration, discrepancies between null and non-null datatypes So I here you ask, what about temporary variables within routines? If ever there was a source of elusive bugs, you'll find it there. Sadly, these temporary variables are not stored in the metadata so we'll have to find a more subtle way of flushing these out, and that will, I'm afraid, have to wait!

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  • Handy SQL Server Function Series: Part 1

    - by Most Valuable Yak (Rob Volk)
    I've been preparing to give a presentation on SQL Server for a while now, and a topic that was recommended was SQL Server functions.  More specifically, the lesser-known functions (like @@OPTIONS), and maybe some interesting ways to use well-known functions (like using PARSENAME to split IP addresses)  I think this is a veritable goldmine of useful information, and researching for the presentation has confirmed that beyond my initial expectations.I even found a few undocumented/underdocumented functions, so for the first official article in this series I thought I'd start with 2 of each, COLLATIONPROPERTY() and COLLATIONPROPERTYFROMID().COLLATIONPROPERTY() provides information about (wait for it) collations, SQL Server's method for handling foreign character sets, sort orders, and case- or accent-sensitivity when sorting character data.  The Books Online entry for  COLLATIONPROPERTY() lists 4 options for code page, locale ID, comparison style and version.  Used in conjunction with fn_helpcollations():SELECT *, COLLATIONPROPERTY(name,'LCID') LCID, COLLATIONPROPERTY(name,'CodePage') CodePage, COLLATIONPROPERTY(name,'ComparisonStyle') ComparisonStyle, COLLATIONPROPERTY(name,'Version') Version FROM fn_helpcollations()You can get some excellent information. (c'mon, be honest, did you even know about fn_helpcollations?)Collations in SQL Server have a unique name and ID, and you'll see one or both in various system tables or views like syscolumns, sys.columns, and INFORMATION_SCHEMA.COLUMNS.  Unfortunately they only link the ID and name for collations of existing columns, so if you wanted to know the collation ID of Albanian_CI_AI_WS, you'd have to declare a column with that collation and query the system table.While poking around the OBJECT_DEFINITION() of sys.columns I found a reference to COLLATIONPROPERTYFROMID(), and the unknown property "Name".  Not surprisingly, this is how sys.columns finds the name of the collation, based on the ID stored in the system tables.  (Check yourself if you don't believe me)Somewhat surprisingly, the "Name" property also works for COLLATIONPROPERTY(), although you'd already know the name at that point.  Some wild guesses and tests revealed that "CollationID" is also a valid property for both functions, so now:SELECT *, COLLATIONPROPERTY(name,'LCID') LCID, COLLATIONPROPERTY(name,'CodePage') CodePage, COLLATIONPROPERTY(name,'ComparisonStyle') ComparisonStyle, COLLATIONPROPERTY(name,'Version') Version, COLLATIONPROPERTY(name,'CollationID') CollationID FROM fn_helpcollations() Will get you the collation ID-name link you…probably didn't know or care about, but if you ever get on Jeopardy! and this question comes up, feel free to send some of your winnings my way. :)And last but not least, COLLATIONPROPERTYFROMID() uses the same properties as COLLATIONPROPERTY(), so you can use either one depending on which value you have available.Keep an eye out for Part 2!

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  • Android Actionbar Tabs + Fragments + Service

    - by Vladimir
    So, I have 3 problems with my code: 1) I want that each tab saves its state. So that a TextView shows changed text if it was changed. 2) if I go to Tab2 then to Tab1 I can't see the content of the fragments. Only if I touch on the already selected tab, it shows me the content 3) I can't correctly connect/bind and unbind service to Fragment Text must be changed from Service. Please help, I don't know how I realize my intent. MyActivity.java package com.example.tabs; import android.app.ActionBar; import android.app.ActionBar.Tab; import android.app.Activity; import android.app.ActivityManager; import android.app.ActivityManager.RunningServiceInfo; import android.app.Fragment; import android.app.FragmentTransaction; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.content.SharedPreferences; import android.os.Bundle; import android.os.Handler; import android.os.IBinder; import android.os.Message; public class MyActivity extends Activity { private static String ACTION_BAR_INDEX = "ACTION_BAR_INDEX"; private Tab tTab1; private Tab tTab2; private static MyService.MyBinder myBinder; private static Intent myServiceIntent; private static MyService myService; private TabListener<Tab1> tab1Listener; private TabListener<Tab2> tab2Listener; private static ServiceConnection myConnection = new ServiceConnection() { public void onServiceConnected(ComponentName name, IBinder binder) { myBinder = (MyService.MyBinder) binder; myService = myBinder.getService(); myBinder.setCallbackHandler(myServiceHandler); } public void onServiceDisconnected(ComponentName name) { myService = null; myBinder = null; } }; /** Callbackhandler. */ private static Handler myServiceHandler = new Handler() { public void handleMessage(Message message) { super.handleMessage(message); Bundle bundle = message.getData(); if (bundle != null) { String text = bundle.getString("Text1", ""); if (!text.equals("")) { } } } }; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); myServiceIntent = new Intent(this, MyService.class); bindService(myServiceIntent, myConnection, Context.BIND_AUTO_CREATE); if (!isServiceRunning()) { startService(myServiceIntent); } final ActionBar actionBar = getActionBar(); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); actionBar.setDisplayShowTitleEnabled(false); tTab1 = actionBar.newTab(); tab1Listener = new TabListener<Tab1>(this, R.id.fl_main, Tab1.class); tTab1.setTag("Tab_1"); tTab1.setText("Tab_1"); tTab1.setTabListener(tab1Listener); tTab2 = actionBar.newTab(); tab2Listener = new TabListener<Tab2>(this, R.id.fl_main, Tab2.class); tTab2.setTag("Tab_2"); tTab2.setText("Tab_2"); tTab2.setTabListener(tab2Listener); actionBar.addTab(tTab1, 0); actionBar.addTab(tTab2, 1); } @Override public void onResume() { super.onResume(); SharedPreferences sp = getPreferences(Activity.MODE_PRIVATE); int actionBarIndex = sp.getInt(ACTION_BAR_INDEX, 0); getActionBar().setSelectedNavigationItem(actionBarIndex); } protected void onSaveInstanceState(Bundle outState) { // Save the current Action Bar tab selection int actionBarIndex = getActionBar().getSelectedTab().getPosition(); SharedPreferences.Editor editor = getPreferences(Activity.MODE_PRIVATE).edit(); editor.putInt(ACTION_BAR_INDEX, actionBarIndex); editor.apply(); // Detach each of the Fragments FragmentTransaction ft = getFragmentManager().beginTransaction(); if (tab2Listener.fragment != null) { ft.detach(tab2Listener.fragment); } if (tab1Listener.fragment != null) { ft.detach(tab1Listener.fragment); } ft.commit(); super.onSaveInstanceState(outState); } protected void onRestoreInstanceState(Bundle savedInstanceState) { // Find the recreated Fragments and assign them to their associated Tab // Listeners. tab1Listener.fragment = getFragmentManager().findFragmentByTag(Tab1.class.getName()); tab2Listener.fragment = getFragmentManager().findFragmentByTag(Tab2.class.getName()); // Restore the previous Action Bar tab selection. SharedPreferences sp = getPreferences(Activity.MODE_PRIVATE); int actionBarIndex = sp.getInt(ACTION_BAR_INDEX, 0); getActionBar().setSelectedNavigationItem(actionBarIndex); super.onRestoreInstanceState(savedInstanceState); } public boolean isServiceRunning() { ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE); for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) { if (MyService.class.getName().equals(service.service.getClassName())) { return true; } } return false; } @Override protected void onDestroy() { super.onDestroy(); unbindService(myConnection); stopService(myServiceIntent); } public static class TabListener<T extends Fragment> implements ActionBar.TabListener { private Fragment fragment; private Activity activity; private Class<T> fragmentClass; private int fragmentContainer; public TabListener(Activity activity, int fragmentContainer, Class<T> fragmentClass) { this.activity = activity; this.fragmentContainer = fragmentContainer; this.fragmentClass = fragmentClass; } public void onTabReselected(Tab tab, FragmentTransaction ft) { if (fragment != null) { ft.attach(fragment); } } public void onTabSelected(Tab tab, FragmentTransaction ft) { if (fragment == null) { String fragmentName = fragmentClass.getName(); fragment = Fragment.instantiate(activity, fragmentName); ft.add(fragmentContainer, fragment, fragmentName); } else { ft.detach(fragment); } } public void onTabUnselected(Tab tab, FragmentTransaction ft) { if (fragment != null) { ft.detach(fragment); } } } } MyService.java package com.example.tabs; import android.app.Service; import android.content.Intent; import android.os.Binder; import android.os.Bundle; import android.os.Handler; import android.os.IBinder; import android.os.Message; public class MyService extends Service { private final IBinder myBinder = new MyBinder(); private static Handler myServiceHandler; public IBinder onBind(Intent intent) { return myBinder; } public int onStartCommand(Intent intent, int flags, int startId) { super.onStartCommand(intent, flags, startId); return START_STICKY; } public void sendMessage(String sText, int id) { Bundle bundle = new Bundle(); bundle.putString("Text" + id, sText); Message bundleMessage = new Message(); bundleMessage.setData(bundle); myServiceHandler.sendMessage(bundleMessage); } public class MyBinder extends Binder { public MyService getService() { return MyService.this; } public void setCallbackHandler(Handler myActivityHandler) { myServiceHandler = myActivityHandler; } public void removeCallbackHandler() { myServiceHandler = null; } } } Tab1.java package com.example.tabs; import android.app.Activity; import android.app.Fragment; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.Handler; import android.os.IBinder; import android.os.Message; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class Tab1 extends Fragment { public static String TAG = Tab1.class.getClass().getSimpleName(); private static TextView tvText; private EditText editText; private static MyService.MyBinder myBinder; private static Intent myServiceIntent; private static MyService myService; private static ServiceConnection myConnection = new ServiceConnection() { public void onServiceConnected(ComponentName name, IBinder binder) { myBinder = (MyService.MyBinder) binder; myService = myBinder.getService(); myBinder.setCallbackHandler(myServiceHandler); } public void onServiceDisconnected(ComponentName name) { myService = null; myBinder = null; } }; /** Callbackhandler. */ private static Handler myServiceHandler = new Handler() { public void handleMessage(Message message) { super.handleMessage(message); Bundle bundle = message.getData(); if (bundle != null) { String text = bundle.getString("Text1", ""); if (!text.equals("")) { tvText.setText(text); } } } }; public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.tab1, container, false); tvText = (TextView) view.findViewById(R.id.tv_tab1); editText = (EditText) view.findViewById(R.id.editText1); Button btn1 = (Button) view.findViewById(R.id.btn_change_text_1); btn1.setOnClickListener(new OnClickListener() { public void onClick(View v) { myService.sendMessage(String.valueOf(editText.getText()), 1); } }); return view; } @Override public void onAttach(Activity activity) { super.onAttach(activity); myServiceIntent = new Intent(activity, MyService.class); activity.bindService(myServiceIntent, myConnection, Context.BIND_AUTO_CREATE); } @Override public void onDetach() { super.onDetach(); getActivity().unbindService(myConnection); } } Tab2.java package com.example.tabs; import android.app.Activity; import android.app.Fragment; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.ServiceConnection; import android.os.Bundle; import android.os.Handler; import android.os.IBinder; import android.os.Message; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; public class Tab2 extends Fragment { public static String TAG = Tab2.class.getClass().getSimpleName(); private static TextView tvText; private EditText editText; private static MyService.MyBinder myBinder; private static Intent myServiceIntent; private static MyService myService; private static ServiceConnection myConnection = new ServiceConnection() { public void onServiceConnected(ComponentName name, IBinder binder) { myBinder = (MyService.MyBinder) binder; myService = myBinder.getService(); myBinder.setCallbackHandler(myServiceHandler); } public void onServiceDisconnected(ComponentName name) { myService = null; myBinder = null; } }; /** Callbackhandler. */ private static Handler myServiceHandler = new Handler() { public void handleMessage(Message message) { super.handleMessage(message); Bundle bundle = message.getData(); if (bundle != null) { String text = bundle.getString("Text1", ""); if (!text.equals("")) { tvText.setText(text); } } } }; public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.tab2, container, false); tvText = (TextView) view.findViewById(R.id.tv_tab2); editText = (EditText) view.findViewById(R.id.editText2); Button btn2 = (Button) view.findViewById(R.id.btn_change_text_2); btn2.setOnClickListener(new OnClickListener() { public void onClick(View v) { myService.sendMessage(String.valueOf(editText.getText()), 2); } }); return view; } @Override public void onAttach(Activity activity) { super.onAttach(activity); myServiceIntent = new Intent(activity, MyService.class); activity.bindService(myServiceIntent, myConnection, Context.BIND_AUTO_CREATE); } @Override public void onDetach() { super.onDetach(); getActivity().unbindService(myConnection); } } main.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/main" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/black" android:orientation="vertical" > </LinearLayout> tab1.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:gravity="center" android:orientation="vertical" > <EditText android:id="@+id/editText1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:ems="10" android:inputType="text" > <requestFocus /> </EditText> <Button android:id="@+id/btn_change_text_1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:text="Change text" /> <TextView android:id="@+id/tv_tab1" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="TAB1\nTAB1\nTAB1" /> </LinearLayout> tab2.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_gravity="center" android:gravity="center" android:orientation="vertical" > <EditText android:id="@+id/editText2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:ems="10" android:inputType="text" > <requestFocus /> </EditText> <Button android:id="@+id/btn_change_text_2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:text="Change text" /> <TextView android:id="@+id/tv_tab2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginBottom="10dp" android:text="TAB2\nTAB2\nTAB2" /> </LinearLayout> AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.tabs" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="15" android:targetSdkVersion="17" /> <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="TabsPlusService" android:theme="@android:style/Theme.Holo" > <activity android:name="com.example.tabs.MyActivity" android:configChanges="orientation|keyboardHidden|screenSize" android:label="TabsPlusService" android:theme="@android:style/Theme.Holo" > <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> <service android:name=".MyService" android:enabled="true" > </service> </application> </manifest>

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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  • How to assign class property as display data member in datagridview

    - by KoolKabin
    hi guys, I am trying to display my data in datagridview. I created a class with different property and used its list as the datasource. it worked fine. but I got confused how to do that in case we have nested class. My Classes are as follows: class Category property UIN as integer property Name as string end class class item property uin as integer property name as string property mycategory as category end class my data list as follows: dim myDataList as list(of Item) = new List(of Item) myDataList.Add(new Item(1,"item1",new category(1,"cat1"))) myDataList.Add(new Item(2,"item2",new category(1,"cat1"))) myDataList.Add(new Item(3,"item3",new category(1,"cat1"))) myDataList.Add(new Item(4,"item4",new category(2,"cat2"))) myDataList.Add(new Item(5,"item5",new category(2,"cat2"))) myDataList.Add(new Item(6,"item6",new category(2,"cat2"))) Now I binded the datagridview control like: DGVMain.AutoGenerateColumns = False DGVMain.ColumnCount = 3 DGVMain.Columns(0).DataPropertyName = "UIN" DGVMain.Columns(0).HeaderText = "ID" DGVMain.Columns(1).DataPropertyName = "Name" DGVMain.Columns(1).HeaderText = "Name" DGVMain.Columns(2).DataPropertyName = "" **'here i want my category name** DGVMain.Columns(2).HeaderText = "category" DGVMain.datasource = myDataList DGVMain.refresh() I have tried using mycategory.name but it didn't worked. What can be done to get expected result? Is there any better idea other than this to accomplish the same task? Edited My question as per comment: I have checked the link given by u. It was nice n very usefull. Since the code was in c# i tried to convert it in vb. Everything went good but failed at a point of case sensitive and next one is that i had my nested class name itemcategory and my property name was category. there it arouse the problem. it didn't searched for category but it searched for itemcategory. so confused on it. My Code as follows: Private Sub DGVMain_CellFormatting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) Handles DGVMain.CellFormatting Dim DGVMain As DataGridView = CType(sender, DataGridView) e.Value = EvaluateValue(DGVMain.Rows(e.RowIndex).DataBoundItem, DGVMain.Columns(e.ColumnIndex).DataPropertyName) End Sub Private Function EvaluateValue(ByRef myObj As Object, ByRef myProp As String) As String Dim Ret As String = "" Dim Props As System.Reflection.PropertyInfo() Dim PropA As System.Reflection.PropertyInfo Dim ObjA As Object If myProp.Contains(".") Then myProp = myProp.Substring(0, myProp.IndexOf(".")) Props = myObj.GetType().GetProperties() For Each PropA In Props ObjA = PropA.GetValue(myObj, New Object() {}) If ObjA.GetType().Name = myProp Then Ret = EvaluateValue(ObjA, myProp.Substring(myProp.IndexOf(".") + 1)) Exit For End If Next Else PropA = myObj.GetType().GetProperty(myProp) Ret = PropA.GetValue(myObj, New Object() {}).ToString() End If Return Ret End Function

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  • How to increment counters based on a printed array

    - by Sam Liew
    I managed to developed a simple board of 5x5 using random numbers and array. Big achievement for someone like me! :) Now I have to increment the counters depending on the frequency of the numbers. If the value within 0-49 is printed..then nCounter++ If the value within 50-75 is printed..then pCounter++ something like that. The problem is that I don't know how to increase the counters based on the printed board. Here is the code: #include <stdio.h> #include <stdlib.h> #include <time.h> int main() { //Initialize Variables int randomNumber; int rows; int columns; int hdCounter =0; int hCounter = 0; int cCounter = 0; int pCounter = 0; int nCounter = 0; //Declare board size int board[5][5]; //size of board is 5 x 5 //Create the random number generator seed srand(time(NULL)); //Assign the random numbers from 1 - 25 into variable randomNumber //Create the rows for the board for ( rows = 1; rows <= 5 ; rows++ ) { //Create the colimns for the board for ( columns = 1; columns <= 5 ; columns++ ) { //Assign variable randomNumber into variable board randomNumber = rand() %100 + 1; board[rows][columns] = randomNumber; //print the board printf("%d\t", board[rows][columns]); //calculate the frequency of numbers on the printed board if (randomNumber >= 85 && randomNumber <= 100 ) hdCounter++; else if ( randomNumber >= 75 ) hCounter++; else if ( randomNumber >= 65 ) cCounter++; else if ( randomNumber >= 50 ) pCounter++; else if ( randomNumber >= 1 ) nCounter++; else continue; } //Newline after the end of 5th column. printf("\n\n"); } printf( "N \t P \t C \t H \t HD\n\n" ); printf("%d \t %d \t %d \t %d \t %d \t", nCounter, pCounter, cCounter, hCounter, hdCounter); }//end main I tried replacing randomNumber in the if-statement with board[rows][columns] but I seem to get the same undesired results.

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  • Reading column header and column values of a data table using LAMBDA(C#3.0)

    - by Newbie
    Consider the folowing where I am reading the data table values and writing to a text file using (StreamWriter sw = new StreamWriter(@"C:\testwrite.txt",true)) { DataPreparation().AsEnumerable().ToList().ForEach(i => { string col1 = i[0].ToString(); string col2 = i[1].ToString(); string col3 = i[2].ToString(); string col4 = i[3].ToString(); sw.WriteLine( col1 + "\t" + col2 + "\t" + col3 + "\t" + col4 + Environment.NewLine ); }); } The data preparation function is as under private static DataTable DataPreparation() { DataTable dt = new DataTable(); dt.Columns.Add("Col1", typeof(string)); dt.Columns.Add("Col2", typeof(int)); dt.Columns.Add("Col3", typeof(DateTime)); dt.Columns.Add("Col4", typeof(bool)); for (int i = 0; i < 10; i++) { dt.Rows.Add("String" + i.ToString(), i, DateTime.Now.Date, (i % 2 == 0) ? true : false); } return dt; } It is working fine. Now in the above described program, it is known to me the Number of columns and the column headers. How to achieve the same in case when the column headers and number of columns are not known at compile time using the lambda expression? I have already done that which is as under public static void WriteToTxt(string directory, string FileName, DataTable outData, string delimiter) { FileStream fs = null; StreamWriter streamWriter = null; using (fs = new FileStream(directory + "\\" + FileName + ".txt", FileMode.Append, FileAccess.Write)) { try { streamWriter = new StreamWriter(fs); streamWriter.BaseStream.Seek(0, SeekOrigin.End); streamWriter.WriteLine(); DataTableReader datatableReader = outData.CreateDataReader(); for (int header = 0; header < datatableReader.FieldCount; header++) { streamWriter.Write(outData.Columns[header].ToString() + delimiter); } streamWriter.WriteLine(); int row = 0; while (datatableReader.Read()) { for (int field = 0; field < datatableReader.FieldCount; field++) { streamWriter.Write(outData.Rows[row][field].ToString() + delimiter); } streamWriter.WriteLine(); row++; } } catch (Exception ex) { throw ex; } } } I am using C#3.0 and framework 3.5 Thanks in advance

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  • Flex DataGrid not Displaying Data

    - by asawilliams
    I have a custom dataGrid that acts more like a 2D list (if that makes sense at all). I am dynamically creating the columns and recreating the dataProvider to suit my needs. While debugging I can see that I am creating the columns and setting them to the dataGrid and creating and setting the dataProvider, but for some reason I am able to see the dataGrid and the columns but not the data. [Bindable] private var mockData:ArrayCollection = new ArrayCollection([ {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}, {value: "425341*"}]); ... <TwoDimensionalList width="100%" height="100%" numColumns="7" numRows="7" dataField="value" dataProvider="{mockData}"/> The snippet of code from the object only contains the important functions, everything else is not important (getters, setters, etc ...). While debugging I checked all the variables in the functions to make sure they were assigned and a value that I was expecting. [Snippet] public class TwoDimensionalList extends DataGrid { ... /** * Creates and sets properties of columns */ private function createColumns():void { var column:DataGridColumn; var cols:Array = this.columns; for(var i:uint=0; i < numColumns; i++) { column = new DataGridColumn("column"+i.toString()); column.dataField = "column"+i.toString(); cols[i]=column; } this.columns = cols; // go to the current gotoPage(this._currentPageNum); } /** * Sets the data for the dataprovider based on the * number of columns, rows, and page number. * * @param pageNum the page number of the data to be viewed in the DataGrids. */ private function gotoPage(pageNum:uint):void { _currentPageNum = pageNum; var startIndex:uint = (pageNum-1)*numColumns*numRows; var data:ArrayCollection = new ArrayCollection(); for(var i:uint=0; i < numRows; i++) { var obj:Object = new Object(); for(var j:uint=0; j < numColumns; j++) { if((i+(j*numRows)+startIndex) < _dataProvider.length) obj["column"+j.toString()] = String(_dataProvider.getItemAt(i+(j*numRows)+startIndex)["value"]); } data.addItem(obj); } this.dataProvider = data; } }

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  • Vertical Seek not progress value not showing on MainActivity textView

    - by Raju Gujarati
    I am try to display the progress value of the seekBar but when it comes to the execution, there is no update on the value being display on the TextView. I wonder what alternatives than putting two classes onto one big class in order to archive this aim ? The below is my code VerticalSeekBar.java package com.example.imagerotation; import android.content.Context; import android.graphics.Canvas; import android.util.AttributeSet; import android.view.MotionEvent; import android.widget.SeekBar; import android.widget.Toast; public class VerticalSeekBar extends SeekBar { public VerticalSeekBar(Context context) { super(context); } public VerticalSeekBar(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public VerticalSeekBar(Context context, AttributeSet attrs) { super(context, attrs); } protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(h, w, oldh, oldw); } @Override protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(heightMeasureSpec, widthMeasureSpec); setMeasuredDimension(getMeasuredHeight(), getMeasuredWidth()); } protected void onDraw(Canvas c) { c.rotate(-90); c.translate(-getHeight(), 0); super.onDraw(c); } @Override public boolean onTouchEvent(MotionEvent event) { if (!isEnabled()) { return false; } switch (event.getAction()) { case MotionEvent.ACTION_DOWN: case MotionEvent.ACTION_MOVE: case MotionEvent.ACTION_UP: int progress = getMax() - (int) (getMax() * event.getY() / getHeight()); setProgress(progress); onSizeChanged(getWidth(), getHeight(), 0, 0); //Toast.makeText(getContext(), String.valueOf(progress), Toast.LENGTH_SHORT).show(); break; case MotionEvent.ACTION_CANCEL: break; } return true; } } MainActvity.java package com.example.imagerotation; import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; public class MainActivity extends Activity { private VerticalSeekBar seek; private TextView by; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); seek = (VerticalSeekBar)findViewById(R.id.seekBar1); by = (TextView)findViewById(R.id.textView1); by.setText(String.valueOf(seek.getProgress())); } }

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  • how can i show ccessarychecked cell values in alertbox

    - by adnan
    i have created uitableview and cell in uitableview are accessarychecked . i have implemented an action named -(IBAction) checkBoxClicked . what i need is that i wanted to show accessarychecked cell values in alertbox when i click on button this is the code which i have written #import "ViewController.h" @implementation ViewController @synthesize cell; - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 7; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { cell= [tableView dequeueReusableCellWithIdentifier:@"cell"]; if (cell == nil) { cell = [[ UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"cell"]; } cell.textLabel.text = [myarray objectAtIndex:indexPath.row]; /* NSString *imagefile = [[NSBundle mainBundle] pathForResource:@"cellimage" ofType:@"png"]; UIImage *ui = [[UIImage alloc] initWithContentsOfFile:imagefile]; cell.imageView.image = ui;*/ NSString *check = [[NSBundle mainBundle] pathForResource:@"checkbox_not_ticked" ofType:@"png"]; UIImage *bi = [[UIImage alloc] initWithContentsOfFile:check]; cell.imageView.image = bi; cell.accessoryType = UITableViewCellAccessoryNone; return cell; [cell release]; } - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { cell = [tableView cellForRowAtIndexPath:indexPath]; if (cell.accessoryType == UITableViewCellAccessoryNone) { cell.accessoryType = UITableViewCellAccessoryCheckmark; } else { cell.accessoryType = UITableViewCellAccessoryNone; } } -(IBAction) checkBoxClicked { NSArray *array = [[NSArray alloc] initWithArray:[myarray objectAtIndex:cell.accessoryType]:UITableViewCellAccessoryCheckmark]; if (array.cell.accessoryType == UITableViewCellAccessoryCheckmark) { UIAlertView *msg = [[ UIAlertView alloc] initWithTitle:@"selected items are given: " message:array delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil, nil ]; [msg show ]; [msg release]; [myarray release]; } } //-(IBAction)checkBoxClicked{} - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } #pragma mark - View lifecycle - (void)viewDidLoad { myarray = [[NSArray alloc] initWithObjects:@"mondey",@"tuesday", @"wednesday",@"thursday",@"friday",@"saturday",@"sundey", nil]; [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. } - (void)viewDidUnload { [myarray release]; [super viewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; } - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; } - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; } - (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown); } @end

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  • Locking sharepoint list item

    - by user39157
    I have a sharepoint custom list which has 5 columns ..the user should fill in first three columns and the other two should be locked..when the user enters the items and start the workflow if the workflow gets approved the 3 columns should be locked for editing and then the other two should be available for editing . Can someone please tell me how can i achieve this. Thanks

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  • MSFT Excel pivot table links to external data

    - by dreftymac
    Question1: What is the best online forum to ask MSFT Excel questions of the following variety? Question2: How can I link an excel pivot-table to a potentially changing source table without having to re-draw the excel pivot-table layout every time the source table changes data. (Note, the columns are not changing, just the data in the rows). Background: I have an excel 2007 pivot table that is grabbing data from another sheet (an excel "table" ... tables are a new feature of excel 2007). When I change the data in the source table, and then go to the pivot table and press "refresh" ... the pivot table reverts to its "blank" format and requires me to re-drag the columns rows and values. What I want is for the pivot-table to simply re-draw itself without me having to re-create the pivot table layout.

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  • Getting rid of site-specific hotkeys

    - by ZyX
    How do I disable site-specific hotkeys if (and only if) they are already mapped in Opera? For example, I use <C-b> instead of <Right> and <C-h> instead of <BS>. On Stack Overflow/Super User they produce **strong text** and ## Heading ## respectively. I do not want this happen. I can examine Super User/Stack Overflow/some_other_site's javascript and write a userjs to do the job, but this method is not universal. I'm using Opera-10.51_pre6252 in Gentoo Linux.

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  • Excel scatter chart with multiple date ranges

    - by Abiel
    I have multiple blocks of time series data on an Excel sheet, with each block having its own set of dates. For example, I might have dates in column A, values in column B, and then dates in column D and values in column E. The values in B go with the dates in A, and the values in E go with the dates in D. The dates in A and D may not be the same. I would like to create a scatter chart with a time category axis that is the union of my two input date ranges in columns A and D. If I select all the data and then go insert chart (in Excel 2010), Excel treats only column A as the X axis, and looks at D as just another set of values. I can get Excel to do what I want by first just charting columns A and B, then selecting D and E and copy-pasting onto the chart. However, I would like to avoid this two-step procedure if possible.

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  • Getting Custom NSCell with NSButtonCell instance to handle mouse click/mouse events

    - by sidha
    OK I'm really stumped on this one. I want to make a checkbox with a NSTextFieldCell combined together. It's important that the checkbox goes ON if the mouse hits the box, NOT the text. I've accomplished this, more or less, but the issue is receiving the mouse event because I click one checkbox in a row, but ALL of them turn to NSOnState. I will show what I've done and my various failed attempts in order to get this to work. So this is how I've done it so far: header: @interface MyCheckboxCellToo : NSTextFieldCell { NSButtonCell *_checkboxCell; } implementation: - (NSUInteger)hitTestForEvent:(NSEvent *)event inRect:(NSRect)cellFrame ofView:(NSView *)controlView { NSPoint point = [controlView convertPoint:[event locationInWindow] fromView:nil]; NSLog(@"%@", NSStringFromPoint(point)); NSRect checkFrame; NSDivideRect(cellFrame, &checkFrame, &cellFrame, cellFrame.size.height/*3 + [[_checkboxCell image] size].width*/, NSMinXEdge); if (NSMouseInRect(point, checkFrame, [controlView isFlipped])) { // the checkbox, or the small region around it, was hit. so let's flip the state NSCellStateValue checkState = ([_checkboxCell state] == NSOnState) ? NSOffState:NSOnState; [self setState:checkState]; [_checkboxCell setState:checkState]; [controlView setNeedsDisplay:YES]; return NSCellHitTrackableArea; } return [super hitTestForEvent:event inRect:cellFrame ofView:controlView]; } I know I probably shouldn't be doing: [self setState:checkState]; [_checkboxCell setState:checkState]; [controlView setNeedsDisplay:YES]; in there... because the result is that EVERY checkbox in every goes to NSOnState. Is this because cells are re-used? How come the ImageAndTextCell can have different images in the same tableview? How do I handle the mouse event? I have tried: - (BOOL)trackMouse:(NSEvent *)theEvent inRect:(NSRect)cellFrame ofView:(NSView *)controlView untilMouseUp:(BOOL)untilMouseUp { NSLog(@"%s %@", _cmd, theEvent); return [_checkboxCell trackMouse:theEvent inRect:cellFrame ofView:controlView untilMouseUp:untilMouseUp]; // return YES; // return [super trackMouse:theEvent inRect:cellFrame ofView:controlView untilMouseUp:untilMouseUp]; } - (BOOL)startTrackingAt:(NSPoint)startPoint inView:(NSView *)controlView { NSLog(@"%s %@", _cmd, NSStringFromPoint(startPoint)); return [super startTrackingAt:startPoint inView:controlView]; } - (BOOL)continueTracking:(NSPoint)lastPoint at:(NSPoint)currentPoint inView:(NSView *)controlView { NSLog(@"%s %@", _cmd, NSStringFromPoint(currentPoint)); return [super continueTracking:lastPoint at:currentPoint inView:controlView]; } - (void)stopTracking:(NSPoint)lastPoint at:(NSPoint)stopPoint inView:(NSView *)controlView mouseIsUp:(BOOL)flag { NSLog(@"%s %d %@", _cmd, flag, NSStringFromPoint(stopPoint)); } trackMouse: ... DOES gets called but startTrackingAt:..., continueTracking:..., and stopTracking:.... DO NOT get called when I click on the checkbox "hit area" in trackMouse:... I have tried return [_checkboxCell trackMouse:theEvent inRect:cellFrame ofView:controlView untilMouseUp:untilMouseUp]; and return [super trackMouse:theEvent inRect:cellFrame ofView:controlView untilMouseUp:untilMouseUp]; and neither seems to result in the mouse event being handled by the checkbox. How do I get that single checkbox to go NSOnState? I know I'm pretty close but after a lot of doc reading and google searching I haven't been successful at solving this. suggestions and comments welcome.. OK here is a bit more to show creation and destruction of the object.. - (id)init { if ((self = [super init])) { _checkboxCell = [[NSButtonCell alloc] init]; [_checkboxCell setButtonType:NSSwitchButton]; [_checkboxCell setTitle:@""]; [_checkboxCell setTarget:self]; [_checkboxCell setImagePosition:NSImageLeft]; [_checkboxCell setControlSize:NSRegularControlSize]; } return self; } - copyWithZone:(NSZone *)zone { MyCheckboxCellToo *cell = (MyCheckboxCellToo *)[super copyWithZone:zone]; cell->_checkboxCell = [_checkboxCell copyWithZone:zone]; return cell; } - (void)dealloc { [_checkboxCell release]; [super dealloc]; }

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  • Make windows vista file explorer act normally

    - by user25866
    Is there some file I can remove or something I can do to globally ensure that windows visa/xp/etc doesn't do annoying things? Annoying things: 1) Hide the file extension 2) All these "meta" columns I could care less about in "details" view (rating, album, date taken, Assistant's name, Artist, 35mm focal length, City, Other City, etc...). All I want are Name, size, date created, date modified, and file extension. MAYBE file chmod settings. 3) That garbage in the left pane known as "favorite links." (Documents, desktop, photos, music, etc...) 4) Switching between detail view, large icon view, thumbnail view, list view, and tiles when I goto differnt folders, all I want is detail view, with the same columns every time. That's it. I shouldn't have to get third party software to make my file system browseable, but if I need to so be it... Why are all these settings buried away? It feels like I have to apply them onto each folder every time.

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  • Binding DataTable To GridView, But No Rows In GridViewRowCollection Despite GridView Population?

    - by KSwift87
    Problem: I've coded a GridView in the markup in a page. I have coded a DataTable in the code-behind that takes data from a collection of custom objects. I then bind that DataTable to the GridView. (Specific problem mentioned a couple code-snippets below.) GridView Markup: <asp:GridView ID="gvCart" runat="server" CssClass="pList" AutoGenerateColumns="false" DataKeyNames="ProductID"> <Columns> <asp:BoundField DataField="ProductID" HeaderText="ProductID" /> <asp:BoundField DataField="Name" HeaderText="ProductName" /> <asp:ImageField DataImageUrlField="Thumbnail" HeaderText="Thumbnail"></asp:ImageField> <asp:BoundField DataField="Unit Price" HeaderText="Unit Price" /> <asp:TemplateField HeaderText="Quantity"> <ItemTemplate> <asp:TextBox ID="Quantity" runat="server" Text="<%# Bind('Quantity') %>" Width="25px"></asp:TextBox> </ItemTemplate> </asp:TemplateField> <asp:BoundField DataField="Total Price" HeaderText="Total Price" /> </Columns> </asp:GridView> DataTable Code-Behind: private void View(List<OrderItem> cart) { DataSet ds = new DataSet(); DataTable dt = ds.Tables.Add("Cart"); if (cart != null) { dt.Columns.Add("ProductID"); dt.Columns.Add("Name"); dt.Columns.Add("Thumbnail"); dt.Columns.Add("Unit Price"); dt.Columns.Add("Quantity"); dt.Columns.Add("Total Price"); foreach (OrderItem item in cart) { DataRow dr = dt.NewRow(); dr["ProductID"] = item.productId.ToString(); dr["Name"] = item.productName; dr["Thumbnail"] = ResolveUrl(item.productThumbnail); dr["Unit Price"] = "$" + item.productPrice.ToString(); dr["Quantity"] = item.productQuantity.ToString(); dr["Total Price"] = "$" + (item.productPrice * item.productQuantity).ToString(); dt.Rows.Add(dr); } gvCart.DataSource = dt; gvCart.DataBind(); gvCart.Width = 500; for (int counter = 0; counter < gvCart.Rows.Count; counter++) { gvCart.Rows[counter].Cells.Add(Common.createCell("<a href='cart.aspx?action=update&prodId=" + gvCart.Rows[counter].Cells[0].Text + "'>Update</a><br /><a href='cart.aspx?action='action=remove&prodId=" + gvCart.Rows[counter].Cells[0].Text + "/>Remove</a>")); } } } Error occurs below in the foreach - the GridViewRowCollection is empty! private void Update(string prodId) { List<OrderItem> cart = (List<OrderItem>)Session["cart"]; int uQty = 0; foreach (GridViewRow gvr in gvCart.Rows) { if (gvr.RowType == DataControlRowType.DataRow) { if (gvr.Cells[0].Text == prodId) { uQty = int.Parse(((TextBox)gvr.Cells[4].FindControl("Quantity")).Text); } } } Goal: I'm basically trying to find a way to update the data in my GridView (and more importantly my cart Session object) without having to do everything else I've seen online such as utilizing OnRowUpdate, etc. Could someone please tell me why gvCart.Rows is empty and/or how I could accomplish my goal without utilizing OnRowUpdate, etc.? When I execute this code, the GridView gets populated but for some reason I can't access any of its rows in the code-behind.

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  • Recommendations for USB flash drive fast at writing small files

    - by Andrew Bainbridge
    I want a drive that I can be used as my work drive, storing a Subversion repo and sandbox for a small project. I'd also like it to be able to store a DVD rip. At the moment I've got a Super Talent pico-C 8gb. It's fast at reading and writing DVD rips, but the performance on small files (ie less than 4k) is utterly terrible (we're talking floppy disk speeds here). This Ars review measured a similar Super Talent drive and pretty much confirmed my measurements (take a look at the random write speeds on page 5). So, I'm looking for a 8gb or bigger drive that doesn't suck at read and write of small files and still has acceptable performance for very large files.

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  • Task Manager: VM Size smaller than Mem usage?

    - by shoosh
    The windows XP tasks manager can show two different columns regarding the memory usage of the processes. One is called Mem Usage and the other is VM Size (not on by default, you need to activate it) From what I've gathered, VM size is the size of the entire memory space occupied by the process and Mem Usage is the amount of memory currently committed and used. This assumption is verified by most processes when the VM Size is only slightly larger than Mem Usage for instance my Outlook currently has 79,724 K in VM Size and 56,600 K in Mem Usage But it fails for other processes such as Firefox which currently has 171,900 K for Mem Usage and only 156,440 K in VM Size. How can a process use more memory than the amount of virtual memory allocated to it? So Maybe my interpretation of these columns is wrong. What do they actually mean?

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  • Unable to access intel fake RAID 1 array in Fedora 14 after reboot

    - by Sim
    Hello everyone, 1st I am relatively new to linux (but not to *nix). I have 4 disks assembled in the following intel ahci bios fake raid arrays: 2x320GB RAID1 - used for operating systems md126 2x1TB RAID1 - used for data md125 I have used the raid of size 320GB to install my operating system and the second raid I didn't even select during the installation of Fedora 14. After successful partitioning and installation of Fedora, I tried to make the second array available, it was possible to make it visible in linux with mdadm --assembe --scan , after that I created one maximum size partition and 1 maximum size ext4 filesystem in it. Mounted, and used it. After restart - a few I/O errors during boot regarding md125 + inability to mount the filesystem on it and dropped into repair shell. I commented the filesystem in fstab and it booted. To my surprise, the array was marked as "auto read only": [root@localhost ~]# cat /proc/mdstat Personalities : [raid1] md125 : active (auto-read-only) raid1 sdc[1] sdd[0] 976759808 blocks super external:/md127/0 [2/2] [UU] md127 : inactive sdc[1](S) sdd[0](S) 4514 blocks super external:imsm md126 : active raid1 sda[1] sdb[0] 312566784 blocks super external:/md1/0 [2/2] [UU] md1 : inactive sdb[1](S) sda[0](S) 4514 blocks super external:imsm unused devices: <none> [root@localhost ~]# and the partition in it was not available as device special file in /dev: [root@localhost ~]# ls -l /dev/md125* brw-rw---- 1 root disk 9, 125 Jan 6 15:50 /dev/md125 [root@localhost ~]# But the partition is there according to fdisk: [root@localhost ~]# fdisk -l /dev/md125 Disk /dev/md125: 1000.2 GB, 1000202043392 bytes 19 heads, 10 sectors/track, 10281682 cylinders, total 1953519616 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x1b238ea9 Device Boot Start End Blocks Id System /dev/md125p1 2048 1953519615 976758784 83 Linux [root@localhost ~]# I tried to "activate" the array in different ways (I'm not experienced with mdadm and the man page is gigantic so I was only browsing it looking for my answer) but it was impossible - the array would still stay in "auto read only" and the device special file for the partition it will not be in /dev. It was only after I recreated the partition via fdisk that it reappeared in /dev... until next reboot. So, my question is - How do I make the array automatically available after reboot? Here is some additional information: 1st I am able to see the UUID of the array in blkid: [root@localhost ~]# blkid /dev/sdc: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/sdd: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/md126p1: UUID="60C8D9A7C8D97C2A" TYPE="ntfs" /dev/md126p2: UUID="3d1b38a3-b469-4b7c-b016-8abfb26a5d7d" TYPE="ext4" /dev/md126p3: UUID="1Msqqr-AAF8-k0wi-VYnq-uWJU-y0OD-uIFBHL" TYPE="LVM2_member" /dev/mapper/vg00-rootlv: LABEL="_Fedora-14-x86_6" UUID="34cc1cf5-6845-4489-8303-7a90c7663f0a" TYPE="ext4" /dev/mapper/vg00-swaplv: UUID="4644d857-e13b-456c-ac03-6f26299c1046" TYPE="swap" /dev/mapper/vg00-homelv: UUID="82bd58b2-edab-4b4b-aec4-b79595ecd0e3" TYPE="ext4" /dev/mapper/vg00-varlv: UUID="1b001444-5fdd-41b6-a59a-9712ec6def33" TYPE="ext4" /dev/mapper/vg00-tmplv: UUID="bf7d2459-2b35-4a1c-9b81-d4c4f24a9842" TYPE="ext4" /dev/md125: UUID="b9a1149f-ae11-4fc8-a600-0d77354dc42a" SEC_TYPE="ext2" TYPE="ext3" /dev/sda: TYPE="isw_raid_member" /dev/md125p1: UUID="420adfdd-6c4e-4552-93f0-2608938a4059" TYPE="ext4" [root@localhost ~]# Here is how /etc/mdadm.conf looks like: [root@localhost ~]# cat /etc/mdadm.conf # mdadm.conf written out by anaconda MAILADDR root AUTO +imsm +1.x -all ARRAY /dev/md1 UUID=89f60dee:e46a251f:7475814b:d4cc19a9 ARRAY /dev/md126 UUID=a8775c90:cee66376:5310fc13:63bcba5b ARRAY /dev/md125 UUID=b9a1149f:ae114fc8:a6000d77:354dc42a [root@localhost ~]# here is how /proc/mdstat looks like after I recreate the partition in the array so that it becomes available: [root@localhost ~]# cat /proc/mdstat Personalities : [raid1] md125 : active raid1 sdc[1] sdd[0] 976759808 blocks super external:/md127/0 [2/2] [UU] md127 : inactive sdc[1](S) sdd[0](S) 4514 blocks super external:imsm md126 : active raid1 sda[1] sdb[0] 312566784 blocks super external:/md1/0 [2/2] [UU] md1 : inactive sdb[1](S) sda[0](S) 4514 blocks super external:imsm unused devices: <none> [root@localhost ~]# Detailed output regarding the array in subject: [root@localhost ~]# mdadm --detail /dev/md125 /dev/md125: Container : /dev/md127, member 0 Raid Level : raid1 Array Size : 976759808 (931.51 GiB 1000.20 GB) Used Dev Size : 976759940 (931.51 GiB 1000.20 GB) Raid Devices : 2 Total Devices : 2 Update Time : Fri Jan 7 00:38:00 2011 State : clean Active Devices : 2 Working Devices : 2 Failed Devices : 0 Spare Devices : 0 UUID : 30ebc3c2:b6a64751:4758d05c:fa8ff782 Number Major Minor RaidDevice State 1 8 32 0 active sync /dev/sdc 0 8 48 1 active sync /dev/sdd [root@localhost ~]# and /etc/fstab, with /data commented (the filesystem that is on this array): # # /etc/fstab # Created by anaconda on Thu Jan 6 03:32:40 2011 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/vg00-rootlv / ext4 defaults 1 1 UUID=3d1b38a3-b469-4b7c-b016-8abfb26a5d7d /boot ext4 defaults 1 2 #UUID=420adfdd-6c4e-4552-93f0-2608938a4059 /data ext4 defaults 0 1 /dev/mapper/vg00-homelv /home ext4 defaults 1 2 /dev/mapper/vg00-tmplv /tmp ext4 defaults 1 2 /dev/mapper/vg00-varlv /var ext4 defaults 1 2 /dev/mapper/vg00-swaplv swap swap defaults 0 0 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0 [root@localhost ~]# Thanks in advance to everyone that even read this whole issue :-)

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  • Can Excel sorts be saved and used again?

    - by Robert Kerr
    On an Excel 2007 worksheet, I have several tables, each sharing the same columns. For every table, I sort in several particular ways, depending on the task at hand. It gets tedious going to the Data tab, clicking Sort, unchecking the "my data has headers" checkbox, then add/removing the columns and ordering sort criteria. Is it possible to: * Save a given sort criteria (a named sort)? * Apply the sort against any selected range? * Create a button to execute each saved sort? In the end, I would create 4 or 5 named sorts and a button for each on the worksheet. Then would be able to select any range of rows, from any table, and click one of the sort buttons. The sort would execute.

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