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  • SQL SERVER – ORDER BY ColumnName vs ORDER BY ColumnNumber

    - by pinaldave
    I strongly favor ORDER BY ColumnName. I read one of the blog post where blogger compared the performance of the two SELECT statement and come to conclusion that ColumnNumber has no harm to use it. Let us understand the point made by first that there is no performance difference. Run following two scripts together: USE AdventureWorks GO -- ColumnName (Recommended) SELECT * FROM HumanResources.Department ORDER BY GroupName, Name GO -- ColumnNumber (Strongly Not Recommended) SELECT * FROM HumanResources.Department ORDER BY 3,2 GO If you look at the result and see the execution plan you will see that both of the query will take the same amount of the time. However, this was not the point of this blog post. It is not good enough to stop here. We need to understand the advantages and disadvantages of both the methods. Case 1: When Not Using * and Columns are Re-ordered USE AdventureWorks GO -- ColumnName (Recommended) SELECT GroupName, Name, ModifiedDate, DepartmentID FROM HumanResources.Department ORDER BY GroupName, Name GO -- ColumnNumber (Strongly Not Recommended) SELECT GroupName, Name, ModifiedDate, DepartmentID FROM HumanResources.Department ORDER BY 3,2 GO Case 2: When someone changes the schema of the table affecting column order I will let you recreate the example for the same. If your development server where your schema is different than the production server, if you use ColumnNumber, you will get different results on the production server. Summary: When you develop the query it may not be issue but as time passes by and new columns are added to the SELECT statement or original table is re-ordered if you have used ColumnNumber it may possible that your query will start giving you unexpected results and incorrect ORDER BY. One should note that the usage of ORDER BY ColumnName vs ORDER BY ColumnNumber should not be done based on performance but usability and scalability. It is always recommended to use proper ORDER BY clause with ColumnName to avoid any confusion. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • select columns by a conact text as columnname in oracle

    - by glaudiston
    I have a table with columns named with the number of hour of day like this: col00 NUMBER(5) col01 NUMBER(5) col02 NUMBER(5) ... col23 NUMBER(5) ...and I have another query that returns a count by hour. I want to recover the colXX value by hour.... then I can recover with "decode" or "case when..." but I want know if exists any way to recover the column by a text like this: select "col"||hour from table; in the hypothetical above example if hour is 13 then would be translated like: select col13 from table; there is any way to do this ?

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  • SQL SERVER – Finding Different ColumnName From Almost Identitical Tables

    - by pinaldave
    I have mentioned earlier on this blog that I love social media – Facebook and Twitter. I receive so many interesting questions that sometimes I wonder how come I never faced them in my real life scenario. Well, let us see one of the similar situation. Here is one of the questions which I received on my social media handle. “Pinal, I have a large database. I did not develop this database but I have inherited this database. In our database we have many tables but all the tables are in pairs. We have one archive table and one current table. Now here is interesting situation. For a while due to some reason our organization has stopped paying attention to archive data. We did not archive anything for a while. If this was not enough we  even changed the schema of current table but did not change the corresponding archive table. This is now becoming a huge huge problem. We know for sure that in current table we have added few column but we do not know which ones. Is there any way we can figure out what are the new column added in the current table and does not exist in the archive tables? We cannot use any third party tool. Would you please guide us?” Well here is the interesting example of how we can use sys.column catalogue views and get the details of the newly added column. I have previously written about EXCEPT over here which is very similar to MINUS of Oracle. In following example we are going to create two tables. One of the tables has extra column. In our resultset we will get the name of the extra column as we are comparing the catalogue view of the column name. USE AdventureWorks2012 GO CREATE TABLE ArchiveTable (ID INT, Col1 VARCHAR(10), Col2 VARCHAR(100), Col3 VARCHAR(100)); CREATE TABLE CurrentTable (ID INT, Col1 VARCHAR(10), Col2 VARCHAR(100), Col3 VARCHAR(100), ExtraCol INT); GO -- Columns in ArchiveTable but not in CurrentTable SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'ArchiveTable' EXCEPT SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'CurrentTable' GO -- Columns in CurrentTable but not in ArchiveTable SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'CurrentTable' EXCEPT SELECT name ColumnName FROM sys.columns WHERE OBJECT_NAME(OBJECT_ID) = 'ArchiveTable' GO DROP TABLE ArchiveTable; DROP TABLE CurrentTable; GO The above query will return us following result. I hope this solves the problems. It is not the most elegant solution ever possible but it works. Here is the puzzle back to you – what native T-SQL solution would you have provided in this situation? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology

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  • SQL SERVER – Rename Columnname or Tablename – SQL in Sixty Seconds #032 – Video

    - by pinaldave
    We all make mistakes at some point of time and we all change our opinion. There are quite a lot of people in the world who have changed their name after they have grown up. Some corrected their parent’s mistake and some create new mistake. Well, databases are not protected from such incidents. There are many reasons why developers may want to change the name of the column or table after it was initially created. The goal of this video is not to dwell on the reasons but to learn how we can rename the column and table. Earlier I have written the article on this subject over here: SQL SERVER – How to Rename a Column Name or Table Name. I have revised the same article over here and created this video. There is one very important point to remember that by changing the column name or table name one creates the possibility of errors in the application the columns and tables are used. When any column or table name is changed, the developer should go through every place in the code base, ad-hoc queries, stored procedures, views and any other place where there are possibility of their usage and change them to the new name. If this is one followed up religiously there are quite a lot of changes that application will stop working due to this name change.  One has to remember that changing column name does not change the name of the indexes, constraints etc and they will continue to reference the old name. Though this will not stop the show but will create visual un-comfort as well confusion in many cases. Here is my question back to you – have you changed ever column name or table name in production database (after project going live)? If yes, what was the scenario and need of doing it. After all it is just a name. Let me know what you think of this video. Here is the updated script. USE tempdb GO CREATE TABLE TestTable (ID INT, OldName VARCHAR(20)) GO INSERT INTO TestTable VALUES (1, 'First') GO -- Check the Tabledata SELECT * FROM TestTable GO -- Rename the ColumnName sp_RENAME 'TestTable.OldName', 'NewName', 'Column' GO -- Check the Tabledata SELECT * FROM TestTable GO -- Rename the TableName sp_RENAME 'TestTable', 'NewTable' GO -- Check the Tabledata - Error SELECT * FROM TestTable GO -- Check the Tabledata - New SELECT * FROM NewTable GO -- Cleanup DROP TABLE NewTable GO Related Tips in SQL in Sixty Seconds: SQL SERVER – How to Rename a Column Name or Table Name What would you like to see in the next SQL in Sixty Seconds video? 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 Tagged: Excel

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  • SQL SERVER – Validating Unique Columnname Across Whole Database

    - by pinaldave
    I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. Asker: “Our business requirement is when we add new column we want it unique across current database.” Pinal: “Why do you have such requirement?” Asker: “Do you know the solution?” Pinal: “Sure I can come up with the answer but it will help me to come up with an optimal answer if I know the business need.” Asker: “Thanks – what will be the answer in that case.” Pinal: “Honestly I am just curious about the reason why you need your column name to be unique across database.” (Silence) Pinal: “Alright – here is the answer – I guess you do not want to tell me reason.” Option 1: Check if Column Exists in Current Database IF EXISTS (  SELECT * FROM sys.columns WHERE Name = N'NameofColumn') BEGIN SELECT 'Column Exists' -- add other logic END ELSE BEGIN SELECT 'Column Does NOT Exists' -- add other logic END Option 2: Check if Column Exists in Current Database in Specific Table IF EXISTS (  SELECT * FROM sys.columns WHERE Name = N'NameofColumn' AND OBJECT_ID = OBJECT_ID(N'tableName')) BEGIN SELECT 'Column Exists' -- add other logic END ELSE BEGIN SELECT 'Column Does NOT Exists' -- add other logic END I guess user did not want to share the reason why he had a unique requirement of having column name unique across databases. Here is my question back to you – have you faced a similar situation ever where you needed unique column name across a database. If not, can you guess what could be the reason for this kind of requirement?  Additional Reference: SQL SERVER – Query to Find Column From All Tables of Database Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL System Table, SQL Tips and Tricks, T SQL, Technology

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  • Handle ConstraintException and get ColumnName that cause the error

    - by Mysterious
    Hello, I have a Table Machines that made of: ID = Identity , Primary , AutoIncrement,NOT NULL SN = Unique , String , NOT NULL Name =String now I am using a form to insert data into this table, and I am using BindingSource and ErrorProvider, I am handling Null and Empty string in the DataSet layer (partial class in the dataset.xsd), now when I try to end editing this.machinesBindingSource.EndEdit(); I got this error message: ex.Message = "Column 'SN' is constrained to be unique. Value '123' is already present." I know I entered a duplicated value but the question is HOW can I determine which the columnName that cause the error and re-write the error message entirely in different language I want to get the columnName and the wrong value thanks in advance

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  • Select row data as ColumnName and Value

    - by Bobcat1506
    I have a history table and I need to select the values from this table in ColumnName, ColumnValue form. I am using SQL Server 2008 and I wasn’t sure if I could use the PIVOT function to accomplish this. Below is a simplified example of what I need to accomplish: This is what I have: The table’s schema is CREATE TABLE TABLE1 (ID INT PRIMARY KEY, NAME VARCHAR(50)) The “history” table’s schema is CREATE TABLE TABLE1_HISTORY( ID INT, NAME VARCHAR(50), TYPE VARCHAR(50), TRANSACTION_ID VARCHAR(50)) Here is the data from TABLE1_HISTORY ID NAME TYPE TRANSACTION_ID 1 Joe INSERT a 1 Bill UPDATE b 1 Bill DELETE c I need to extract the data from TABLE1_HISTORY into this format: TransactionId Type ColumnName ColumnValue a INSERT ID 1 a INSERT NAME Joe b UPDATE ID 1 b UPDATE NAME Bill c DELETE ID 1 c DELETE NAME Bill Other than upgrading to Enterprise Edition and leveraging the built in change tracking functionality, what is your suggestion for accomplishing this task?

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  • SSIS: "Failure inserting into the read-only column <ColumnName>"

    - by Cory
    I have an Excel source going into an OLE DB destination. I'm inserting data into a view that has an INSTEAD OF trigger that handles all inserts. When I try to execute the package I receive this error: "Failure inserting into the read-only column ColumnName" What can I do to let SSIS know that this view is safe to insert into because there is an INSTEAD OF trigger that will handle the insert? EDIT (Additional info): Some more additional info. I have a flat file that is being inserted into a normalized database. My initial problem was how do I take a flat file and insert that data into multiple tables while keeping track of all the primary/foreign key relationships. My solution was to create a VIEW that mimicked the structure of the flat file and then create an INSTEAD OF trigger on that view. In my INSTEAD OF trigger I would handle the logic of maintaining all the relationships between tables My view looks something like this. CREATE VIEW ImportView AS SELECT CONVERT(varchar(100, NULL) AS CustomerName, CONVERT(varchar(100), NULL) AS Address1, CONVERT(varchar(100), NULL) AS Address2, CONVERT(varchar(100), NULL) AS City, CONVERT(char(2), NULL) AS State, CONVERT(varchar(250), NULL) AS ItemOrdered, CONVERT(int, NULL) AS QuantityOrdered ... I will never need to select from this view, I only use it to insert data into it from this flat file I receive. I need someway to tell SQL Server that the fields aren't really read only because there is an INSTEAD OF trigger on this view.

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  • Problem with WHERE columnName = Data in MySQL query in C#

    - by Ryan Sullivan
    I have a C# webservice on a Windows Server that I am interfacing with on a linux server with PHP. The PHP grabs information from the database and then the page offers a "more information" button which then calls the webservice and passes in the name field of the record as a parameter. So i am using a WHERE statement in my query so I only pull the extra fields for that record. I am getting the error: System.Data.SqlClient.SqlException:Invalid column name '42' Where 42 is the value from the name field from the database. my query is string selectStr = "SELECT name, castNotes, triviaNotes FROM tableName WHERE name =\"" + show + "\""; I do not know if it is a problem with my query or something is wrong with the database, but here is the rest of my code for reference. NOTE: this all works perfectly when I grab all of the records, but I only want to grab the record that I ask my webservice for. public class ktvService : System.Web.Services.WebService { [WebMethod] public string moreInfo(string show) { string connectionStr = "MyConnectionString"; string selectStr = "SELECT name, castNotes, triviaNotes FROM tableName WHERE name =\"" + show + "\""; SqlConnection conn = new SqlConnection(connectionStr); SqlDataAdapter da = new SqlDataAdapter(selectStr, conn); DataSet ds = new DataSet(); da.Fill(ds, "tableName"); DataTable dt = ds.Tables["tableName"]; DataRow theShow = dt.Rows[0]; string response = "Name: " + theShow["name"].ToString() + "Cast: " + theShow["castNotes"].ToString() + " Trivia: " + theShow["triviaNotes"].ToString(); return response; } }

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  • Separating columnName and Value in C#

    - by KungfuPanda
    hi, I have a employee object as shown below class emp { public int EmpID { get; set; } public string EmpName { get; set; } public int deptID { get; set; } } I need to create a mapping either in this class or a different class to map the properties with column name of my SQL for eg. EmpdID="employeeID" EmpName="EmployeeName" deptID="DepartmentID" When from my asp.net page when I create the employee class and pass it to a function: for eg: emp e=new emp(); e.EmpID=1; e.EmpName="tommy"; e.deptID=10; When the emp object is populated and passed to the buildValues function it should return array of ComumnName(e.g.employeeID):Value(e.g.1),EmployeeName:tommy,DepartmentID:10) string[] values=buildValues(emp); public string[] buildValues(emp e) { string[] values=null; return values; } I have 2 questions: 1. Where do I specify the mappings 2. How do I use the mappings in my buildValues function shown above and build the values string array. I would really appreciate if you can help me with this

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  • Help creating a ColumnName Convention using FluentNHibernate

    - by Rafael E. Belliard
    I've been trying to specify a custom naming convention for my database table columns. So far, I have been able to setup a convention for the table's name, but not the actual columns. I've seen a few guides on the internet, but they're not working using the latest Fluent NHibernate (1.0.0 RTM). public class CamelCaseSplitNamingConvention : IClassConvention, IComponentConvention { public void Apply(IClassInstance instance) { instance.Table(instance.EntityType.Name.ChangeCamelCaseToUnderscore()); } public void Apply(IComponentInstance instance) { // is this the correct call for columns? If not, which one? } } Please help.

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  • select columns by a concat text as columnname in oracle

    - by glaudiston
    I have a table with columns named with the number of hour of day like this: col00 NUMBER(5) col01 NUMBER(5) col02 NUMBER(5) ... col23 NUMBER(5) ...and I have another query that returns a count by hour. I want to recover the colXX value by hour.... then I can recover with "decode" or "case when..." but I want know if exists any way to recover the column by a text like this: select "col"||hour from table; in the hypothetical above example if hour is 13 then would be translated like: select col13 from table; there is any way to do this ?

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  • How to find if dataTable contains column which name starts with abc

    - by VilemRousi
    In my program I have a dataTable and I´d like to know if is there a column which name starts with abc. For example I have a DataTable and its name is abcdef. I like to find this column using something like this: DataTable.Columns.Constains(ColumnName.StartWith(abc)) Because I know only part of the column name, I cannot use a Contains method. Is there any simple way how to do that? Thanks a lot.

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  • Inheritance with POCO entities in Entity Framework 4

    - by Juvaly
    Hi All, I have a Consumer class and a BillableConsumer : Consumer class. When trying to do any operation on my "Consumers" set, I get the error message "Object mapping could not be found for Type with identity Models.BillableConsumer. From the CSDL: <EntityType Name="BillableConsumer" BaseType="Models.Consumer"> <Property Type="String" Name="CardExpiratoin" Nullable="false" /> <Property Type="String" Name="CardNumber" Nullable="false" /> <Property Type="String" Name="City" Nullable="false" /> <Property Type="String" Name="Country" Nullable="false" /> <Property Type="String" Name="CVV" Nullable="false" /> <Property Type="String" Name="NameOnCard" Nullable="false" /> <Property Type="String" Name="PostalCode" Nullable="false" /> <Property Type="String" Name="State" /> <Property Type="String" Name="StreetAddress" Nullable="false" /> </EntityType> From the C-S: <EntitySetMapping Name="Consumers"> <EntityTypeMapping TypeName="IsTypeOf(Models.Consumer)"> <MappingFragment StoreEntitySet="consumer"> <ScalarProperty Name="LoginID" ColumnName="LoginID" /> <ScalarProperty Name="FirstName" ColumnName="FirstName" /> <ScalarProperty Name="LastName" ColumnName="LastName" /> </MappingFragment> </EntityTypeMapping> <EntityTypeMapping TypeName="IsTypeOf(Models.BillableConsumer)"> <MappingFragment StoreEntitySet="billinginformation"> <ScalarProperty Name="CardExpiratoin" ColumnName="CardExpiratoin" /> <ScalarProperty Name="CardNumber" ColumnName="CardNumber" /> <ScalarProperty Name="City" ColumnName="City" /> <ScalarProperty Name="Country" ColumnName="Country" /> <ScalarProperty Name="CVV" ColumnName="CVV" /> <ScalarProperty Name="LoginID" ColumnName="LoginID" /> <ScalarProperty Name="NameOnCard" ColumnName="NameOnCard" /> <ScalarProperty Name="PostalCode" ColumnName="PostalCode" /> <ScalarProperty Name="State" ColumnName="State" /> <ScalarProperty Name="StreetAddress" ColumnName="StreetAddress" /> </MappingFragment> </EntityTypeMapping> </EntitySetMapping> Is this because I did not specifically add the BillableConsumer entity to the object set? How do I do that in a POCO scenario? Thanks! UPDATE: I decided to test whether or not POCOs generated with the T4 template would solve the problem and they did. The most annoying part is that when I restored my original classes from SVN to try and figure out how they are different - they worked as well!! Not adding this as an answer because someone else might have an actual explanation...

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  • What to name column in database table that holds versioning number

    - by rwmnau
    I'm trying to figure out what to call the column in my database table that holds an INT to specific "record version". I'm currently using "RecordOrder", but I don't like that, because people think higher=newer, but the way I'm using it, lower=newer (with "1" being the current record, "2" being the second most current, "3" older still, and so on). I've considered "RecordVersion", but I'm afraid that would have the same problem. Any other suggestions? "RecordAge"? I'm doing this because when I insert into the table, instead of having to find out what version is next, then run the risk of having that number stolen from me before I write, I just insert insert with a "RecordOrder" of 0. There's a trigger on the table AFTER INSERT that increments all the "RecordOrder" numbers for that key by 1, so the record I just inserted becomes "1", and all others are increased by 1. That way, you can get a person's current record by selection RecordOrder=1, instead of getting the MAX(RecordOrder) and then selecting that. PS - I'm also open to criticism about why this is a terrible idea and I should be incrementing this index instead. This just seemed to make lookups much easier, but if it's a bad idea, please enlighten me! Some details about the data, as an example: I have the following database table: CREATE TABLE AmountDue ( CustomerNumber INT, AmountDue DECIMAL(14,2), RecordOrder SMALLINT, RecordCreated DATETIME ) A subset of my data looks like this: CustomerNumber Amountdue RecordOrder RecordCreated 100 0 1 2009-12-19 05:10:10.123 100 10.05 2 2009-12-15 06:12:10.123 100 100.00 3 2009-12-14 14:19:10.123 101 5.00 1 2009-11-14 05:16:10.123 In this example, there are three rows for customer 100 - they owed $100, then $10.05, and now they owe nothing. Let me know if I need to clarify it some more. UPDATE: The "RecordOrder" and "RecordCreated" columns are not available to the user - they're only there for internal use, and to help figure out which is the current customer record. Also, I could use it to return an appropriately-ordered customer history, though I could just as easily do that with the date. I can accomplish the same thing as an incrementing "Record Version" with just the RecordCreated date, I suppose, but that removes the convenience of knowing that RecordOrder=1 is the current record, and I'm back to doing a sub-query with MAX or MIN on the DateTime to determine the most recent record.

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  • C# find a value from an object column using a string from another column

    - by Graham
    I have 2 list in foreach loops.. I currently use a 'switch' statement on the m.columnname and then assign the value of that column to another var map as per below.. If m.columnname = 'DocHeading' then v.docheading is assigned to map.value.. There will always be a match on m.columnname to a column in the var v. is there a way to get the value from the var v using the string from m.columnname? The reason is that the users will want to add and change column names and I dont want to have to change this code all the time.. Hope this makes sense List spreadMapping = new List(); foreach (var m in mappings) { foreach (var v in hvalues) { SpreadMappings map = new SpreadMappings(); switch (m.ColumnName) { case “DocHeading”: map.ColumnX = m.ColumnX; map.ColumnY = m.ColumnY; map.ColumnValue = v.DocHeading; map.ColumnName = m.ColumnName; map.ColumnId = v.Id; map.ColumnSheetName = sheetName; spreadMapping.Add(map); break;

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  • SQL Server script commands to check if object exists and drop it

    - by deadlydog
    Over the past couple years I’ve been keeping track of common SQL Server script commands that I use so I don’t have to constantly Google them.  Most of them are how to check if a SQL object exists before dropping it.  I thought others might find these useful to have them all in one place, so here you go: 1: --=============================== 2: -- Create a new table and add keys and constraints 3: --=============================== 4: IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'TableName' AND TABLE_SCHEMA='dbo') 5: BEGIN 6: CREATE TABLE [dbo].[TableName] 7: ( 8: [ColumnName1] INT NOT NULL, -- To have a field auto-increment add IDENTITY(1,1) 9: [ColumnName2] INT NULL, 10: [ColumnName3] VARCHAR(30) NOT NULL DEFAULT('') 11: ) 12: 13: -- Add the table's primary key 14: ALTER TABLE [dbo].[TableName] ADD CONSTRAINT [PK_TableName] PRIMARY KEY NONCLUSTERED 15: ( 16: [ColumnName1], 17: [ColumnName2] 18: ) 19: 20: -- Add a foreign key constraint 21: ALTER TABLE [dbo].[TableName] WITH CHECK ADD CONSTRAINT [FK_Name] FOREIGN KEY 22: ( 23: [ColumnName1], 24: [ColumnName2] 25: ) 26: REFERENCES [dbo].[Table2Name] 27: ( 28: [OtherColumnName1], 29: [OtherColumnName2] 30: ) 31: 32: -- Add indexes on columns that are often used for retrieval 33: CREATE INDEX IN_ColumnNames ON [dbo].[TableName] 34: ( 35: [ColumnName2], 36: [ColumnName3] 37: ) 38: 39: -- Add a check constraint 40: ALTER TABLE [dbo].[TableName] WITH CHECK ADD CONSTRAINT [CH_Name] CHECK (([ColumnName] >= 0.0000)) 41: END 42: 43: --=============================== 44: -- Add a new column to an existing table 45: --=============================== 46: IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA='dbo' 47: AND TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName') 48: BEGIN 49: ALTER TABLE [dbo].[TableName] ADD [ColumnName] INT NOT NULL DEFAULT(0) 50: 51: -- Add a description extended property to the column to specify what its purpose is. 52: EXEC sys.sp_addextendedproperty @name=N'MS_Description', 53: @value = N'Add column comments here, describing what this column is for.' , 54: @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE', 55: @level1name = N'TableName', @level2type=N'COLUMN', 56: @level2name = N'ColumnName' 57: END 58: 59: --=============================== 60: -- Drop a table 61: --=============================== 62: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'TableName' AND TABLE_SCHEMA='dbo') 63: BEGIN 64: DROP TABLE [dbo].[TableName] 65: END 66: 67: --=============================== 68: -- Drop a view 69: --=============================== 70: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME = 'ViewName' AND TABLE_SCHEMA='dbo') 71: BEGIN 72: DROP VIEW [dbo].[ViewName] 73: END 74: 75: --=============================== 76: -- Drop a column 77: --=============================== 78: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA='dbo' 79: AND TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName') 80: BEGIN 81: 82: -- If the column has an extended property, drop it first. 83: IF EXISTS (SELECT * FROM sys.fn_listExtendedProperty(N'MS_Description', N'SCHEMA', N'dbo', N'Table', 84: N'TableName', N'COLUMN', N'ColumnName') 85: BEGIN 86: EXEC sys.sp_dropextendedproperty @name=N'MS_Description', 87: @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE', 88: @level1name = N'TableName', @level2type=N'COLUMN', 89: @level2name = N'ColumnName' 90: END 91: 92: ALTER TABLE [dbo].[TableName] DROP COLUMN [ColumnName] 93: END 94: 95: --=============================== 96: -- Drop Primary key constraint 97: --=============================== 98: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='PRIMARY KEY' AND TABLE_SCHEMA='dbo' 99: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'PK_Name') 100: BEGIN 101: ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [PK_Name] 102: END 103: 104: --=============================== 105: -- Drop Foreign key constraint 106: --=============================== 107: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='FOREIGN KEY' AND TABLE_SCHEMA='dbo' 108: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'FK_Name') 109: BEGIN 110: ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [FK_Name] 111: END 112: 113: --=============================== 114: -- Drop Unique key constraint 115: --=============================== 116: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' 117: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'UNI_Name') 118: BEGIN 119: ALTER TABLE [dbo].[TableNames] DROP CONSTRAINT [UNI_Name] 120: END 121: 122: --=============================== 123: -- Drop Check constraint 124: --=============================== 125: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='CHECK' AND TABLE_SCHEMA='dbo' 126: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'CH_Name') 127: BEGIN 128: ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [CH_Name] 129: END 130: 131: --=============================== 132: -- Drop a column's Default value constraint 133: --=============================== 134: DECLARE @ConstraintName VARCHAR(100) 135: SET @ConstraintName = (SELECT TOP 1 s.name FROM sys.sysobjects s JOIN sys.syscolumns c ON s.parent_obj=c.id 136: WHERE s.xtype='d' AND c.cdefault=s.id 137: AND parent_obj = OBJECT_ID('TableName') AND c.name ='ColumnName') 138: 139: IF @ConstraintName IS NOT NULL 140: BEGIN 141: EXEC ('ALTER TABLE [dbo].[TableName] DROP CONSTRAINT ' + @ConstraintName) 142: END 143: 144: --=============================== 145: -- Example of how to drop dynamically named Unique constraint 146: --=============================== 147: DECLARE @ConstraintName VARCHAR(100) 148: SET @ConstraintName = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS 149: WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' 150: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME LIKE 'FirstPartOfConstraintName%') 151: 152: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' 153: AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = @ConstraintName) 154: BEGIN 155: EXEC ('ALTER TABLE [dbo].[TableName] DROP CONSTRAINT ' + @ConstraintName) 156: END 157: 158: --=============================== 159: -- Check for and drop a temp table 160: --=============================== 161: IF OBJECT_ID('tempdb..#TableName') IS NOT NULL DROP TABLE #TableName 162: 163: --=============================== 164: -- Drop a stored procedure 165: --=============================== 166: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE='PROCEDURE' AND ROUTINE_SCHEMA='dbo' AND 167: ROUTINE_NAME = 'StoredProcedureName') 168: BEGIN 169: DROP PROCEDURE [dbo].[StoredProcedureName] 170: END 171: 172: --=============================== 173: -- Drop a UDF 174: --=============================== 175: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE='FUNCTION' AND ROUTINE_SCHEMA='dbo' AND 176: ROUTINE_NAME = 'UDFName') 177: BEGIN 178: DROP FUNCTION [dbo].[UDFName] 179: END 180: 181: --=============================== 182: -- Drop an Index 183: --=============================== 184: IF EXISTS (SELECT * FROM SYS.INDEXES WHERE name = 'IndexName') 185: BEGIN 186: DROP INDEX TableName.IndexName 187: END 188: 189: --=============================== 190: -- Drop a Schema 191: --=============================== 192: IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'SchemaName') 193: BEGIN 194: EXEC('DROP SCHEMA SchemaName') 195: END And here’s the same code, just not in the little code view window so that you don’t have to scroll it.--=============================== -- Create a new table and add keys and constraints --=============================== IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'TableName' AND TABLE_SCHEMA='dbo') BEGIN CREATE TABLE [dbo].[TableName]  ( [ColumnName1] INT NOT NULL, -- To have a field auto-increment add IDENTITY(1,1) [ColumnName2] INT NULL, [ColumnName3] VARCHAR(30) NOT NULL DEFAULT('') ) -- Add the table's primary key ALTER TABLE [dbo].[TableName] ADD CONSTRAINT [PK_TableName] PRIMARY KEY NONCLUSTERED ( [ColumnName1],  [ColumnName2] ) -- Add a foreign key constraint ALTER TABLE [dbo].[TableName] WITH CHECK ADD CONSTRAINT [FK_Name] FOREIGN KEY ( [ColumnName1],  [ColumnName2] ) REFERENCES [dbo].[Table2Name]  ( [OtherColumnName1],  [OtherColumnName2] ) -- Add indexes on columns that are often used for retrieval CREATE INDEX IN_ColumnNames ON [dbo].[TableName] ( [ColumnName2], [ColumnName3] ) -- Add a check constraint ALTER TABLE [dbo].[TableName] WITH CHECK ADD CONSTRAINT [CH_Name] CHECK (([ColumnName] >= 0.0000)) END --=============================== -- Add a new column to an existing table --=============================== IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName') BEGIN ALTER TABLE [dbo].[TableName] ADD [ColumnName] INT NOT NULL DEFAULT(0) -- Add a description extended property to the column to specify what its purpose is. EXEC sys.sp_addextendedproperty @name=N'MS_Description',  @value = N'Add column comments here, describing what this column is for.' ,  @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE', @level1name = N'TableName', @level2type=N'COLUMN', @level2name = N'ColumnName' END --=============================== -- Drop a table --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'TableName' AND TABLE_SCHEMA='dbo') BEGIN DROP TABLE [dbo].[TableName] END --=============================== -- Drop a view --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME = 'ViewName' AND TABLE_SCHEMA='dbo') BEGIN DROP VIEW [dbo].[ViewName] END --=============================== -- Drop a column --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS where TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND COLUMN_NAME = 'ColumnName') BEGIN -- If the column has an extended property, drop it first. IF EXISTS (SELECT * FROM sys.fn_listExtendedProperty(N'MS_Description', N'SCHEMA', N'dbo', N'Table', N'TableName', N'COLUMN', N'ColumnName') BEGIN EXEC sys.sp_dropextendedproperty @name=N'MS_Description',  @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE', @level1name = N'TableName', @level2type=N'COLUMN', @level2name = N'ColumnName' END ALTER TABLE [dbo].[TableName] DROP COLUMN [ColumnName] END --=============================== -- Drop Primary key constraint --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='PRIMARY KEY' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'PK_Name') BEGIN ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [PK_Name] END --=============================== -- Drop Foreign key constraint --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='FOREIGN KEY' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'FK_Name') BEGIN ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [FK_Name] END --=============================== -- Drop Unique key constraint --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'UNI_Name') BEGIN ALTER TABLE [dbo].[TableNames] DROP CONSTRAINT [UNI_Name] END --=============================== -- Drop Check constraint --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='CHECK' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = 'CH_Name') BEGIN ALTER TABLE [dbo].[TableName] DROP CONSTRAINT [CH_Name] END --=============================== -- Drop a column's Default value constraint --=============================== DECLARE @ConstraintName VARCHAR(100) SET @ConstraintName = (SELECT TOP 1 s.name FROM sys.sysobjects s JOIN sys.syscolumns c ON s.parent_obj=c.id WHERE s.xtype='d' AND c.cdefault=s.id  AND parent_obj = OBJECT_ID('TableName') AND c.name ='ColumnName') IF @ConstraintName IS NOT NULL BEGIN EXEC ('ALTER TABLE [dbo].[TableName] DROP CONSTRAINT ' + @ConstraintName) END --=============================== -- Example of how to drop dynamically named Unique constraint --=============================== DECLARE @ConstraintName VARCHAR(100) SET @ConstraintName = (SELECT TOP 1 CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS  WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME LIKE 'FirstPartOfConstraintName%') IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_TYPE='UNIQUE' AND TABLE_SCHEMA='dbo' AND TABLE_NAME = 'TableName' AND CONSTRAINT_NAME = @ConstraintName) BEGIN EXEC ('ALTER TABLE [dbo].[TableName] DROP CONSTRAINT ' + @ConstraintName) END --=============================== -- Check for and drop a temp table --=============================== IF OBJECT_ID('tempdb..#TableName') IS NOT NULL DROP TABLE #TableName --=============================== -- Drop a stored procedure --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE='PROCEDURE' AND ROUTINE_SCHEMA='dbo' AND ROUTINE_NAME = 'StoredProcedureName') BEGIN DROP PROCEDURE [dbo].[StoredProcedureName] END --=============================== -- Drop a UDF --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE='FUNCTION' AND ROUTINE_SCHEMA='dbo' AND  ROUTINE_NAME = 'UDFName') BEGIN DROP FUNCTION [dbo].[UDFName] END --=============================== -- Drop an Index --=============================== IF EXISTS (SELECT * FROM SYS.INDEXES WHERE name = 'IndexName') BEGIN DROP INDEX TableName.IndexName END --=============================== -- Drop a Schema --=============================== IF EXISTS (SELECT * FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = 'SchemaName') BEGIN EXEC('DROP SCHEMA SchemaName') END

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  • Using a WPF ListView as a DataGrid

    - by psheriff
    Many people like to view data in a grid format of rows and columns. WPF did not come with a data grid control that automatically creates rows and columns for you based on the object you pass it. However, the WPF Toolkit can be downloaded from CodePlex.com that does contain a DataGrid control. This DataGrid gives you the ability to pass it a DataTable or a Collection class and it will automatically figure out the columns or properties and create all the columns for you and display the data.The DataGrid control also supports editing and many other features that you might not always need. This means that the DataGrid does take a little more time to render the data. If you want to just display data (see Figure 1) in a grid format, then a ListView works quite well for this task. Of course, you will need to create the columns for the ListView, but with just a little generic code, you can create the columns on the fly just like the WPF Toolkit’s DataGrid. Figure 1: A List of Data using a ListView A Simple ListView ControlThe XAML below is what you would use to create the ListView shown in Figure 1. However, the problem with using XAML is you have to pre-define the columns. You cannot re-use this ListView except for “Product” data. <ListView x:Name="lstData"          ItemsSource="{Binding}">  <ListView.View>    <GridView>      <GridViewColumn Header="Product ID"                      Width="Auto"               DisplayMemberBinding="{Binding Path=ProductId}" />      <GridViewColumn Header="Product Name"                      Width="Auto"               DisplayMemberBinding="{Binding Path=ProductName}" />      <GridViewColumn Header="Price"                      Width="Auto"               DisplayMemberBinding="{Binding Path=Price}" />    </GridView>  </ListView.View></ListView> So, instead of creating the GridViewColumn’s in XAML, let’s learn to create them in code to create any amount of columns in a ListView. Create GridViewColumn’s From Data TableTo display multiple columns in a ListView control you need to set its View property to a GridView collection object. You add GridViewColumn objects to the GridView collection and assign the GridView to the View property. Each GridViewColumn object needs to be bound to a column or property name of the object that the ListView will be bound to. An ADO.NET DataTable object contains a collection of columns, and these columns have a ColumnName property which you use to bind to the GridViewColumn objects. Listing 1 shows a sample of reading and XML file into a DataSet object. After reading the data a GridView object is created. You can then loop through the DataTable columns collection and create a GridViewColumn object for each column in the DataTable. Notice the DisplayMemberBinding property is set to a new Binding to the ColumnName in the DataTable. C#private void FirstSample(){  // Read the data  DataSet ds = new DataSet();  ds.ReadXml(GetCurrentDirectory() + @"\Xml\Product.xml");    // Create the GridView  GridView gv = new GridView();   // Create the GridView Columns  foreach (DataColumn item in ds.Tables[0].Columns)  {    GridViewColumn gvc = new GridViewColumn();    gvc.DisplayMemberBinding = new Binding(item.ColumnName);    gvc.Header = item.ColumnName;    gvc.Width = Double.NaN;    gv.Columns.Add(gvc);  }   // Setup the GridView Columns  lstData.View = gv;  // Display the Data  lstData.DataContext = ds.Tables[0];} VB.NETPrivate Sub FirstSample()  ' Read the data  Dim ds As New DataSet()  ds.ReadXml(GetCurrentDirectory() & "\Xml\Product.xml")   ' Create the GridView  Dim gv As New GridView()   ' Create the GridView Columns  For Each item As DataColumn In ds.Tables(0).Columns    Dim gvc As New GridViewColumn()    gvc.DisplayMemberBinding = New Binding(item.ColumnName)    gvc.Header = item.ColumnName    gvc.Width = [Double].NaN    gv.Columns.Add(gvc)  Next   ' Setup the GridView Columns  lstData.View = gv  ' Display the Data  lstData.DataContext = ds.Tables(0)End SubListing 1: Loop through the DataTable columns collection to create GridViewColumn objects A Generic Method for Creating a GridViewInstead of having to write the code shown in Listing 1 for each ListView you wish to create, you can create a generic method that given any DataTable will return a GridView column collection. Listing 2 shows how you can simplify the code in Listing 1 by setting up a class called WPFListViewCommon and create a method called CreateGridViewColumns that returns your GridView. C#private void DataTableSample(){  // Read the data  DataSet ds = new DataSet();  ds.ReadXml(GetCurrentDirectory() + @"\Xml\Product.xml");   // Setup the GridView Columns  lstData.View =      WPFListViewCommon.CreateGridViewColumns(ds.Tables[0]);  lstData.DataContext = ds.Tables[0];} VB.NETPrivate Sub DataTableSample()  ' Read the data  Dim ds As New DataSet()  ds.ReadXml(GetCurrentDirectory() & "\Xml\Product.xml")   ' Setup the GridView Columns  lstData.View = _      WPFListViewCommon.CreateGridViewColumns(ds.Tables(0))  lstData.DataContext = ds.Tables(0)End SubListing 2: Call a generic method to create GridViewColumns. The CreateGridViewColumns MethodThe CreateGridViewColumns method will take a DataTable as a parameter and create a GridView object with a GridViewColumn object in its collection for each column in your DataTable. C#public static GridView CreateGridViewColumns(DataTable dt){  // Create the GridView  GridView gv = new GridView();  gv.AllowsColumnReorder = true;   // Create the GridView Columns  foreach (DataColumn item in dt.Columns)  {    GridViewColumn gvc = new GridViewColumn();    gvc.DisplayMemberBinding = new Binding(item.ColumnName);    gvc.Header = item.ColumnName;    gvc.Width = Double.NaN;    gv.Columns.Add(gvc);  }   return gv;} VB.NETPublic Shared Function CreateGridViewColumns _  (ByVal dt As DataTable) As GridView  ' Create the GridView  Dim gv As New GridView()  gv.AllowsColumnReorder = True   ' Create the GridView Columns  For Each item As DataColumn In dt.Columns    Dim gvc As New GridViewColumn()    gvc.DisplayMemberBinding = New Binding(item.ColumnName)    gvc.Header = item.ColumnName    gvc.Width = [Double].NaN    gv.Columns.Add(gvc)  Next   Return gvEnd FunctionListing 3: The CreateGridViewColumns method takes a DataTable and creates GridViewColumn objects in a GridView. By separating this method out into a class you can call this method anytime you want to create a ListView with a collection of columns from a DataTable. SummaryIn this blog you learned how to create a ListView that acts like a DataGrid. You are able to use a DataTable as both the source of the data, and for creating the columns for the ListView. In the next blog entry you will learn how to use the same technique, but for Collection classes. NOTE: You can download the complete sample code (in both VB and C#) at my website. http://www.pdsa.com/downloads. Choose Tips & Tricks, then "WPF ListView as a DataGrid" from the drop-down. Good Luck with your Coding,Paul Sheriff ** SPECIAL OFFER FOR MY BLOG READERS **Visit http://www.pdsa.com/Event/Blog for a free eBook on "Fundamentals of N-Tier".

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  • Auditing in Entity Framework.

    - by Gabriel Susai
    After going through Entity Framework I have a couple of questions on implementing auditing in Entity Framework. I want to store each column values that is created or updated to a different audit table. Rightnow I am calling SaveChanges(false) to save the records in the DB(still the changes in context is not reset). Then get the added | modified records and loop through the GetObjectStateEntries. But don't know how to get the values of the columns where their values are filled by stored proc. ie, createdate, modifieddate etc. Below is the sample code I am working on it. //Get the changed entires( ie, records) IEnumerable<ObjectStateEntry> changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Modified); //Iterate each ObjectStateEntry( for each record in the update/modified collection) foreach (ObjectStateEntry entry in changes) { //Iterate the columns in each record and get thier old and new value respectively foreach (var columnName in entry.GetModifiedProperties()) { string oldValue = entry.OriginalValues[columnName].ToString(); string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, oldvalue, newvalue } } changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Added); foreach (ObjectStateEntry entry in changes) { if (entry.IsRelationship) continue; var columnNames = (from p in entry.EntitySet.ElementType.Members select p.Name).ToList(); foreach (var columnName in columnNames) { string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, value } }

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  • 'Invalid column name [ColumnName]' on a nested linq query.

    - by Joe
    I've got the following query: ATable .GroupBy(x=> new {FieldA = x.FieldAID, FieldB = x.FieldBID, FieldC = x.FieldCID}) .Select(x=>new {FieldA = x.Key.FieldA, ..., last_seen = x.OrderByDescending(y=>y.Timestamp).FirstOrDefault().Timestamp}) results in: SqlException: Invalid column name 'FieldAID' x 5 SqlException: Invalid column name 'FieldBID' x 5 SqlException: Invalid column name 'FieldCID' x 1 I've worked out it has to do with the last query to Timestamp because this works: ATable .GroupBy(x=> new {FieldA = x.FieldAID, FieldB = x.FieldBID, FieldC = x.FieldCID}) .Select(x=>new {FieldA = x.Key.FieldA, ..., last_seen = x.OrderByDescending(y=>y.Timestamp).FirstOrDefault()}) The query has been simplified. The purpose is to group by a set of variables and then show the last time this grouping occured in the db. I'm using Linqpad 4 to generate these results so the Timestamp gives me a string whereas FirstOrDefault gives me the whole object which isn't ideal. Update On further testing I've noticed that the number and type of SQLException is related to the class created in the groupby clause. So, ATable .GroupBy(x=> new {FieldA = x.FieldAID}) .Select(x=>new {FieldA = x.Key.FieldA, last_seen = x.OrderByDescending(y=>y.Timestamp).FirstOrDefault()}) results in SqlException: Invalid column name 'FieldAID' x 5

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  • jquery get radiobuttonlist by id dynamically

    - by Cindy
    I have two radiobuttonlist and one checkboxlist on the page. Ideally based on the checkbox selected value, I want to enable/disable corresponding radibuttonlist with jquery function. But some how $("input[name*=" + columnName + "]") always return null. It can not find the radiobuttonlist by its name? $(function() { function checkBoxClicked() { var isChecked = $(this).is(":checked"); var columnName = "rblColumn" + $(this).parent().attr("alt"); if (isChecked) { $("input[name*=" + columnName + "]").removeAttr("disabled"); } else { $("input[name*=" + columnName + "]").attr("disabled", "disabled"); $("input[name*=" + columnName + "] input").each(function() { $(this).attr("checked", "") }); } } //intercept any check box click event inside the #list Div $(":checkbox").click(checkBoxClicked); });

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  • Add columnname and data from datatable to a dictionary? C#

    - by Nick
    Hi, I am looping through a datatable and currently I do string customerId = row["CustomerId"].ToString(); string companyName = row["Company Name"].ToString(); Instead of declaring every variable how do I add these do a dictionary? I was thinking something like: foreach (DataRow row in customerTbl.Rows) { Dictionary<string, string> customerDictionary = new Dictionary<string, string>(); customerDictionary.Add(row[].ToString(), row[].ToString()); so yeah, how do I get the row name and value into there? Thanks in advance.

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  • Sending changes from multiple tables in disconnected dataset to SQLServer...

    - by Stecy
    We have a third party application that accept calls using an XML RPC mechanism for calling stored procs. We send a ZIP-compressed dataset containing multiple tables with a bunch of update/delete/insert using this mechanism. On the other end, a CLR sproc decompress the data and gets the dataset. Then, the following code gets executed: using (var conn = new SqlConnection("context connection=true")) { if (conn.State == ConnectionState.Closed) conn.Open(); try { foreach (DataTable table in ds.Tables) { string columnList = ""; for (int i = 0; i < table.Columns.Count; i++) { if (i == 0) columnList = table.Columns[0].ColumnName; else columnList += "," + table.Columns[i].ColumnName; } var da = new SqlDataAdapter("SELECT " + columnList + " FROM " + table.TableName, conn); var builder = new SqlCommandBuilder(da); builder.ConflictOption = ConflictOption.OverwriteChanges; da.RowUpdating += onUpdatingRow; da.Update(ds, table.TableName); } } catch (....) { ..... } } Here's the event handler for the RowUpdating event: public static void onUpdatingRow(object sender, SqlRowUpdatingEventArgs e) { if ((e.StatementType == StatementType.Update) && (e.Command == null)) { e.Command = CreateUpdateCommand(e.Row, sender as SqlDataAdapter); e.Status = UpdateStatus.Continue; } } and the CreateUpdateCommand method: private static SqlCommand CreateUpdateCommand(DataRow row, SqlDataAdapter da) { string whereClause = ""; string setClause = ""; SqlConnection conn = da.SelectCommand.Connection; for (int i = 0; i < row.Table.Columns.Count; i++) { char quoted; if ((row.Table.Columns[i].DataType == Type.GetType("System.String")) || (row.Table.Columns[i].DataType == Type.GetType("System.DateTime"))) quoted = '\''; else quoted = ' '; string val = row[i].ToString(); if (row.Table.Columns[i].DataType == Type.GetType("System.Boolean")) val = (bool)row[i] ? "1" : "0"; bool isPrimaryKey = false; for (int j = 0; j < row.Table.PrimaryKey.Length; j++) { if (row.Table.PrimaryKey[j].ColumnName == row.Table.Columns[i].ColumnName) { if (whereClause != "") whereClause += " AND "; if (row[i] == DBNull.Value) whereClause += row.Table.Columns[i].ColumnName + "=NULL"; else whereClause += row.Table.Columns[i].ColumnName + "=" + quoted + val + quoted; isPrimaryKey = true; break; } } /* Only values for column that is not a primary key can be modified */ if (!isPrimaryKey) { if (setClause != "") setClause += ", "; if (row[i] == DBNull.Value) setClause += row.Table.Columns[i].ColumnName + "=NULL"; else setClause += row.Table.Columns[i].ColumnName + "=" + quoted + val + quoted; } } return new SqlCommand("UPDATE " + row.Table.TableName + " SET " + setClause + " WHERE " + whereClause, conn); } However, this is really slow when we have a lot of records. Is there a way to optimize this or an entirely different way to send lots of udpate/delete on several tables? I would really much like to use TSQL for this but can't figure a way to send a dataset to a regular sproc. Additional notes: We cannot directly access the SQLServer database. We tried without compression and it was slower.

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  • How to edit the code table for one row only?

    - by TomatoSandwich
    I understand that dw-control.Object.columnname.Values("Red~tR/Blue~tB) changes columnname's values for all rows, but is there code that can just change the dropdown values of a code table for specific row/s? I've tried dw-control.Object.columnname[row].Values but I get R0039 in response :(

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  • Printing a DataTable to textbox/textfile in .NET

    - by neodymium
    Is there a predefined or "easy" method of writing a datatable to a text file or TextBox Control (With monospace font) such as DataTable.Print(): Column1| Column2| --------|--------| v1| v2| v3| v4| v5| v6| Edit Here's an initial version (vb.net) - in case anyone is interested or wants to build their own: Public Function BuildTable(ByVal dt As DataTable) As String Dim result As New StringBuilder Dim widths As New List(Of Integer) Const ColumnSeparator As Char = "|"c Const HeadingUnderline As Char = "-"c ' determine width of each column based on widest of either column heading or values in that column For Each col As DataColumn In dt.Columns Dim colWidth As Integer = Integer.MinValue For Each row As DataRow In dt.Rows Dim len As Integer = row(col.ColumnName).ToString.Length If len > colWidth Then colWidth = len End If Next widths.Add(CInt(IIf(colWidth < col.ColumnName.Length, col.ColumnName.Length + 1, colWidth + 1))) Next ' write column headers For Each col As DataColumn In dt.Columns result.Append(col.ColumnName.PadLeft(widths(col.Ordinal))) result.Append(ColumnSeparator) Next result.AppendLine() ' write heading underline For Each col As DataColumn In dt.Columns Dim horizontal As String = New String(HeadingUnderline, widths(col.Ordinal)) result.Append(horizontal.PadLeft(widths(col.Ordinal))) result.Append(ColumnSeparator) Next result.AppendLine() ' write each row For Each row As DataRow In dt.Rows For Each col As DataColumn In dt.Columns result.Append(row(col.ColumnName).ToString.PadLeft(widths(col.Ordinal))) result.Append(ColumnSeparator) Next result.AppendLine() Next Return result.ToString() End Function

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