Search Results

Search found 8603 results on 345 pages for 'altering tables'.

Page 96/345 | < Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >

• How to setup relationships in contact Database

  - by Walt

  I am currently embarking on a new venture to learn PHP and MySQL. I have done some simple databases in the past using Access, but this one is to be a web-centric database for tracking a myriad of data including contacts and project information. I will need to link the various tables in various relationships, and I am not sure the best way to do that. Since I am just starting out with PHP/MySQL I am researching online sources for learning as much as possible. If anyone has recommendations on books or websites, I would appreciate it. In setting up my tables, one major area that I am concerned with is contacts. I will have a variety of contacts that include: employees, clients, vendors, subcontractors, etc.. and a single contact can be multiple types and each type would have various additional fields that pertain to them. My thought was to have one contacts table that links to other tables for the various contact types. I'm not sure which field type or setup of table options are best... Thoughts? This scenario will likely play out in other areas of the database as well for projects and products. Any pointers/direction would be appreciated. WES

  Read the article

• Validating Login / Changing User settings / Php Mysql

  - by Marcelo

  Hi everyone, my questions are about login, and changing already saved data. (Q1) 'Till now I've only saved input in the tables of the database (registration steps), now I need to check if the input (login steps), are the same of my table in database, in fact I have 3 types of users, then I'll have to check 3 kind of tables. Then if the input data matches with one of those 3 tables I will redirect the user to his specific area. I'm thinking about saved the submitted data $login=$_REQUEST['login']; and $password=$_REQUEST['password']; and compare with the login column in the database. Then if the login matches, I'll compare the password submitted with the one in the row, not in the column. But I don't know how to do this search and comparison,neither what to use. Then if both matches I'll redirect the user. Else I'll send an login error message. (this I know how to do) (Q2) What if need to change an already saved user ? For example to change an email address. My changing user's data web page is exactly the same like the registration user web page. Can I load the already saved options and values of registration (table user for example). Then the user will change whatever he thinks it's necessary, and then when he submits the new information, they would not create a new row in my table, but just be overwritten the old information? How can I do this? Sorry for any mistake in English, and Thanks for the attention.

  Read the article

• Weird MySQL behavior, seems like a SQL bug

  - by Daniel Magliola

  I'm getting a very strange behavior in MySQL, which looks like some kind of weird bug. I know it's common to blame the tried and tested tool for one's mistakes, but I've been going around this for a while. I have 2 tables, I, with 2797 records, and C, with 1429. C references I. I want to delete all records in I that are not used by C, so i'm doing: select * from i where id not in (select id_i from c); That returns 0 records, which, given the record counts in each table, is physically impossible. I'm also pretty sure that the query is right, since it's the same type of query i've been using for the last 2 hours to clean up other tables with orphaned records. To make things even weirder... select * from i where id in (select id_i from c); DOES work, and brings me the 1297 records that I do NOT want to delete. So, IN works, but NOT IN doesn't. Even worse: select * from i where id not in ( select i.id from i inner join c ON i.id = c.id_i ); That DOES work, although it should be equivalent to the first query (i'm just trying mad stuff at this point). Alas, I can't use this query to delete, because I'm using the same table i'm deleting from in the subquery. I'm assuming something in my database is corrupt at this point. In case it matters, these are all MyISAM tables without any foreign keys, whatsoever, and I've run the same queries in my dev machine and in the production server with the same result, so whatever corruption there might be survived a mysqldump / source cycle, which sounds awfully strange. Any ideas on what could be going wrong, or, even more importantly, how I can fix/work around this? Thanks! Daniel

  Read the article

• C# DynamicPDF Merging causing "Index out of bounds" error

  - by Dining Philanderer

  Greetings, We use DynamicPDF to merge multiple PDF documents stored in a MSSQL database. The vast majority of times it works wonderfully, but occasionally one of these documents will fail to merge generating the exception message "Index was outside the bounds of the array." I think I have isolated the problem to PDF files that are greater than 8.5 x 11.0. Does anyone know if this is a known issue with DynamicPDF? The merging code is posted here. What would be ideal is if there is a way to resize the PDF files to the correct size so this is not a concern at all... for (int docs = 0; docs < dsPDFInfo.Tables[0].Rows.Count; docs++) { byte[] bytePDFArray = (byte[])dsPDFInfo.Tables[0].Rows[docs]["Content"]; int iContentSize = Convert.ToInt32(dsPDFInfo.Tables[0].Rows[docs]["ContentSize"]); MemoryStream ms = new MemoryStream(bytePDFArray, 0, iContentSize); ceTe.DynamicPDF.Merger.PdfDocument pdfdoc = new ceTe.DynamicPDF.Merger.PdfDocument(ms); ceTe.DynamicPDF.Merger.MergeDocument mergedoc = new ceTe.DynamicPDF.Merger.MergeDocument(pdfdoc); docCombinedPDF.Append(mergedoc); } Thanks....

  Read the article

• MySQL Paritioning performance

  - by Imran Pathan

  Measured performance on key partitioned tables and normal tables separately. But we couldn't find any performance improvement with partitioning. Queries are pruned. Using MySQL 5.1.47 on RHEL 4. Table details: UserUsage - Will have entries for user mobile number and data usage for each date. Mobile number and Date as PRI KEY. UserProfile - Queries prev table and stores summary for each mobile number. Mobile number PRI KEY. CREATE TABLE `UserUsage` ( `Msisdn` decimal(20,0) NOT NULL, `Date` date NOT NULL, . . PRIMARY KEY USING BTREE (`Msisdn`,`Date`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 PARTITION BY KEY(Msisdn) PARTITIONS 50; CREATE TABLE `UserProfile` ( `Msisdn` decimal(20,0) NOT NULL, . . PRIMARY KEY (`Msisdn`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 PARTITION BY KEY(Msisdn) PARTITIONS 50; Second table is updated by query select and order by date in first table in a perl program, query is select * from UserUsage where Msisdn=number order by Date desc limit 7 [Process data in perl] update UserProfile values(....) where Msisdn=number explain partition for select, shows row being scanned in a particular partition only. Is something wrong with partition design or queries as partitioning is taking almost same or more time compared to normal tables?

  Read the article

• MYSQL JOIN WHERE ISSUES - need some kind of if condition

  - by Breezer

  Hi Well this will be hard to explain but ill do my best The thing is i have 4 tables all with a specific column to relate to eachother. 1 table with users(agent_users) , 1 with working hours(agent_pers), 1 with sold items(agent_stat),1 with project(agent_pro) the user and the project table is irrelevant in the issue at hand but to give you a better understanding why certain tables is included in my query i decided to still mention them =) The thing is that I use 2 pages to insert data to the working hour and the sold items during that time tables, then i have a third page to summarize everything for current month, the query for that is as following: SELECT *, SUM(sv_p_kom),SUM(sv_p_gick),SUM(sv_p_lunch) FROM (( agent_users LEFT JOIN agent_pers ON agent_users.sv_aid = agent_pers.sv_p_uid) LEFT JOIN agent_stat ON agent_pers.sv_p_uid = agent_stat.sv_s_uid) LEFT JOIN agent_pro ON agent_pers.sv_p_pid=agent_pro.p_id WHERE MONTH(agent_pers.sv_p_datum) =7 GROUP BY sv_aname so the problem is now that i dont want sold items from previous months to get included in the data received, i know i could solve that by simple adding in the WHERE part MONTH(agent_stat.sv_s_datum) =7 but then if no items been sold that month no data at all will show up not the time or anything. Any aid on how i could solve this is greatly appreciated. if there's something that's not so clear dont hesitate to ask and ill try my best to answer. after all my english isn't the best out there :P regards breezer

  Read the article

• problem with phpMyAdmin advanced features

  - by typoknig

  Hi all, I am having trouble putting the final touches on my MySQL/Apache/phpMyAdmin install on a Windows XP system. I am trying to get rid of all the error message in phpMyAdmin and I have gotten rid of all of them except the ones related to "advanced features." The exact error message I have is : The additional features for working with linked tables have been deactivated. To find out why click here. I have read up on the cause of the errors but I must be missing something because I still cannot get the warning to go away. Here is what I have done: Created a linked-tables infrastructure (default name "phpmyadmin") per the phpMyAdmin instructions and enabled "pmadb" in my "config.inc.php" file. Specified (enabled) the table names in my "config.inc.php" file (there are 9 tables total). Created a "controluser" and granted only Select privilages per phpMyAdmin instructions Adjusted "controluser" pma and "controlpass" pmapass in "config.inc.php" file From what I can see these are all the instruction phpMyAdmin gives on this subject, and I am unable to locate any tutorials on the specifics of "advanced features" in phpMyAdmin. Any help would be appreciated, and be gentle, this is my first go with MySQL/phpMyAdmin

  Read the article

• What is preferred strategies for cross browser and multiple styled table in CSS?

  - by jitendra

  What is preferred strategies for cross browser and multiple styled table in CSS? in default css what should i predefined for <table>, td, th , thead, tbody, tfoot I have to work in a project there are so many tables with different color schemes and different type of alignment like in some table , i will need to horizontally align data of cell to right, sometime left, sometime right. same thing for vertical alignment, top, bottom and middle. some table will have thin border on row , some will have thick (same with column border). Some time i want to give different background color to particular row or column or in multiple row or column. So my question is: What code should i keep in css default for all tables and how to handle table with different style using ID and classes in multiple pages. I want to do every presentational thing with css. How to make ID classes for everything using semantic naming ? Which tags related to table can be useful? How to control whole tables styling from one css class?

  Read the article

• Is it possible to filter data used by pivot table based on filtering the rows in a source table in Excel?

  - by Geoffrey Stoel

  I have developed a dashboard in Excel 2007 that uses one source table in a sheet (being filled with a query on our data warehouse) and multiple pivot tables making different cross sections on this data. I use the GETPIVOTDATA in almost a hundred formulas to give me the right value for a specific indicator in my dashboard. This all works fine. However I now have received the question to make the dashboard for 5 different segments. As you can imagine I don't want to create 5 different workbooks for this and need to maintain the dashboard logic on all of them. So my question is the following. Is it possible to automatically (through VBA or any other means) filter the results in my source table which is the source for my pivot tables and thus for my dashboard values. So schematically: DATABASE_VIEW -- SOURCE_TABLE -- 12 pivot tables -- 100 GETPIVOTDATA functions Preferably I would like to load all the segments in the source_table (one view on my database) and then filter the data in the source table, which results in filterd source_dat for my pivots. This way I can (without requerying the db) quickly change between segments in the dashboards (refreshing pivots only). Data in the source table has the column: CUSTOMER_SEGMENT available to filter upon. Any help is appreciated. Geoffrey

  Read the article

• Database schema for a library

  - by ABach

  Hi all - I'm designing a library management system for a department at my university and I wanted to enlist your eyes on my proposed schema. This post is primarily concerned with how we store multiple copies of each book; something about what I've designed rubs me the wrong way, and I'm hoping you all can point out better ways to tackle things. For dealing with users checking out books, I've devised three tables: book, customer, and book_copy. The relationships between these tables are as follows: Every book has many book_copies (to avoid duplicating the book's information while storing the fact that we have multiple copies of that book). Every user has many book_copies (the other end of the relationship) The tables themselves are designed like this: ------------------------------------------------ book ------------------------------------------------ + id + title + author + isbn + etc. ------------------------------------------------ ------------------------------------------------ customer ------------------------------------------------ + id + first_name + first_name + email + address + city + state + zip + etc. ------------------------------------------------ ------------------------------------------------ book_copy ------------------------------------------------ + id + book_id (FK to book) + customer_id (FK to customer) + checked_out + due_date + etc. ------------------------------------------------ Something about this seems incorrect (or at least inefficient to me) - the perfectionist in me feels like I'm not normalizing this data correctly. What say ye? Is there a better, more effective way to design this schema? Thanks!

  Read the article

• mysql: storing arbitrary data

  - by Hailwood

  Background: I was asking a question on stack overflow regarding creating tables on the fly where this conversation ensued: This smells like a terrible idea! In fact, it smells just like this one. What in the world do you want to use this for? – deceze @deceze: very true, However, How else would you store the contents of these CSV files. They must be stored in mysql for indexing. The only solid fact about them is that they all have a mobile column with a standard format. The CSV can have an arbitrary amount of columns with an arbitrary amount of rows. They can (with no exaggeration) range from a single row, 35 column csv to an 80k row single column CSV. I am open to other ideas. – Hailwood There are many solutions for this, from attribute-value schemas to JSON storage and NoSQL storage. Open a new question about it. Whatever you do though, don't dynamically create tables! – deceze Question: So my question is, What would you say is the best way to store this data? Are you in agreement with deceze about not creating dynamic tables?

  Read the article

• DO NOT BOTHER. THE PROBLEM IS NOT TRANSACTIONS. DUNNO HOW TO CLOSE / DELETE

  - by matti

  THE PROBLEM IS SOLVED. I DUNNO HOW TO CLOSE THIS QUESTION. ANOTHER SERVICE IS PROPABLY RUNNING AT ALMOST SAME SYNC THAT DOES THE THING. MY WORK "MATE" WILL HEAR A THING OR TWO IN THE MORNING. I have following code in windows service: data is in the dataset and it has been populated earlier and then rows are updated and inserted to dataset tables before calling code below. using (dataSetTxn = _cnctn.BeginTransaction()) { try { _somePlanAdptr.UpdateCommand.Transaction = dataSetTxn; _someLogAdptr.InsertCommand.Transaction = dataSetTxn; _someLinkAdptr.InsertCommand.Transaction = dataSetTxn; _someDataAdptr.InsertCommand.Transaction = dataSetTxn; _log.WriteDebug("Updating SomePlanAction"); _somePlanAdptr.Update(_ofDataSet, "SomePlanAction"); _log.WriteDebug(string.Format("Inserting {0} rows to SomeLog")); //error _someLogAdptr.Update(_ofDataSet, "SomeLog"); _log.WriteDebug(string.Format("Updating SomeLink with {0} rows", _ofDataSet.Tables["SomeLink"].Rows.Count)); _someLinkAdptr.Update(_ofDataSet, "SomeLink"); _log.WriteDebug(string.Format("Updating SomeData with {0} rows", _ofDataSet.Tables["SomeData"].Rows.Count)); _someDataAdptr.Update(_ofDataSet, "SomeData"); _log.WriteDebug("Commiting all changes to database."); dataSetTxn.Commit(); } catch (Exception e) { _log.WriteError("Updating database failed -> rollback", e); if (dataSetTxn != null && _cnctn.State == ConnectionState.Open) dataSetTxn.Rollback(); throw e; } } so one of the lines causes an exception log.WriteDebug(string.Format("Inserting {0} rows to SomeLog")); //error still the first adapter's data is updated to database. when debugged the data is not yet updated until the method that calls all (including this bit) exits. The method that does all is timed with System.Threading.Timer. Thanks & BR -Matti

  Read the article

• MS Access: Permission problems with views

  - by Keith Williams

  "I'll use an Access ADP" I said, "it's only a tiny project and I've got better things to do", I said, "I can build an interface really quickly in Access" I said. </sarcasm> Sorry for the rant, but it's Friday, I have a date in just under two hours, and I'm here late because this just isn't working - so, in despair, I turn to SO for help. Access ADP front-end, linked to a SQL Server 2008 database Using a SQL Server account to log into the database (for testing); this account is a member of the role, "Api"; this role has SELECT, EXECUTE, INSERT, UPDATE, DELETE access to the "Api" schema The "Api" schema is owned by "dbo" All tables have a corresponding view in the Api schema: e.g. dbo.Customer -- Api.Customers The rationale is that users don't have direct table access, but can deal with views as if they were tables I can log into SQL using my test login, and it works fine: no access to the tables, but I can select, insert, update and delete from the Api views. In Access, I see the views, I can open them, but whenever I try to insert or update, I get the following error: The SELECT permission was denied on the object '[Table name which the view is using]', database '[database name]', schema 'dbo' Crazy as it sounds, Access seems to be trying to access the underlying table rather than the view. Any ideas?

  Read the article

• design an extendable database model

  - by wishi_

  Hi! Currently I'm doing a project whose specifications are unclear - well who doesn't. I wonder what's the best development strategy to design a DB, that's going to be extended sooner or later with additional tables and relations. I want to include "changeability". My main concern is that I want to apply design patterns (it's a university project) and I want to separate the constant factors from those, that change by choosing appropriate design patterns - in my case MVC and a set of sub-patterns at model level. When it comes to the DB however, I may have to resdesign my model in my MVC approach, because my domain model at a later stage my require a different set of classes representing the DB tables. I use Hibernate as an abstraction layer between DB and application. Would you start with a very minimal DB, just a few tables and relations? And what if I want an efficient DB, too? I wonder what strategies are applied in the real world. Stakeholder analysis for example isn't a sufficient planing solution when it comes to changing requirements. I think - at a DB level - my design pattern ends. So there's breach whose impact I'd like to minimize with a smart strategy.

  Read the article

• Table not created by Hibernate

  - by User1

  I annotated a bunch of POJO's so JPA can use them to create tables in Hibernate. It appears that all of the tables are created except one very central table called "Revision". The Revision class has an @Entity(name="RevisionT") annotation so it will be renamed to RevisionT so there is not a conflict with any reserved words in MySQL (the target database). I delete the entire database, recreate it and basically open and close a JPA session. All the tables seem to get recreated without a problem. Why would a single table be missing from the created schema? What instrumentation can be used to see what Hibernate is producing and which errors? Thanks. UPDATE: I tried to create as a Derby DB and it was successful. However, one of the fields has a a name of "index". I use @org.hibernate.annotations.IndexColumn to specify the name to something other than a reserved word. However, the column is always called "index" when it is created. Here's a sample of the suspect annotations. @ManyToOne @JoinColumn(name="MasterTopID") @IndexColumn(name="Cx3tHApe") protected MasterTop masterTop; Instead of creating MasterTop.Cx3tHApe as a field, it creates MasterTop.Index. Why is the name ignored?

  Read the article

• Export the datagrid data to text in asp.net+c#.net

  - by SRIRAM

  Problem:It will asks there is no assembly reference/namespace for Database Database db = DatabaseFactory.CreateDatabase(); DBCommandWrapper selectCommandWrapper = db.GetStoredProcCommandWrapper("sp_GetLatestArticles"); DataSet ds = db.ExecuteDataSet(selectCommandWrapper); StringBuilder str = new StringBuilder(); for(int i=0;i<=ds.Tables[0].Rows.Count - 1; i++) { for(int j=0;j<=ds.Tables[0].Columns.Count - 1; j++) { str.Append(ds.Tables[0].Rows[i][j].ToString()); } str.Append("<BR>"); } Response.Clear(); Response.AddHeader("content-disposition", "attachment;filename=FileName.txt"); Response.Charset = ""; Response.Cache.SetCacheability(HttpCacheability.NoCache); Response.ContentType = "application/vnd.text"; System.IO.StringWriter stringWrite = new System.IO.StringWriter(); System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite); Response.Write(str.ToString()); Response.End();

  Read the article

• .NET 3.5 DataGridView Wont Save To Database

  - by Jimbo

  I have created a test Winforms application in Visual Studio 2008 (SP1) to see just how "RAD" C# and .NET 3.5 can be. So far I have mixed emotions. Added a service-based database to my application (MyDB.mdf) and added two tables - Contact (id [identity], name [varchar] and number [varchar] columns) and Group (id [identity] and name [varchar] columns) Added a DataSource, selected "Database" as the source, used the default connection string as the connection (which points to my database) and selected "All Tables" to be included in the data source and saved as MyDBDataSet Expanded the data source showing my two tables, selected the "Group" table and chose to display it as a DataGridView (from the dropdown option on the right of each entity) and dragged it onto Form1, thus creating a groupBindingNavigator, groupBindingSource, groupTableAdapter, tableAdapterManager, myDBDataset and groupDataGridView Press F5 to test the application, enter the name "Test" under the DataGridView's "name" column and click "Save" on the navigator which has autogenerated code to save the data that looks like this: private void groupBindingNavigatorSaveItem_Click(object sender, EventArgs e) { this.Validate(); this.groupBindingSource.EndEdit(); this.tableAdapterManager.UpdateAll(this.myDBDataSet); } Stop the application and have a look at the database data, you will see no data saved there in the "Group" table. I dont know why and cant find out how to fix it! Googled for about 30 minutes with no luck. The code is auto-generated with the controls, so you'd think that it would work too :)

  Read the article

• Snapshot agent obliterates conflicts

  - by mwolfe02

  We are using merge replication in SQL Server 2000. We have a snapshot agent that runs every night that updates the publication snapshot. About six months ago we updated from SQL Server 7.0 to 2000 (that's not a typo). We noticed a sharp decline in conflicts at that time but could not track down the reason. We finally found that the daily snapshot agent is recreating the conflict tables every night. This seems to be a change in functionality from SQL Server 7.0. We were running the snapshot agent before and the conflicts would accumulate. Is there some way to prevent the data in the conflict tables from being lost when the snapshot runs? Can anyone confirm a change in behavior between 7.0 and 2000? Our current plan is to simply stop automatically updating the publication snapshot. Is that a reasonable workaround? Here is the line from the script that is adding the snapshot: exec sp_addpublication_snapshot @publication = N'MyPub' , @frequency_type = 4 , @frequency_interval = 1 , @frequency_relative_interval = 1 , @frequency_recurrence_factor = 0 , @frequency_subday = 1 , @frequency_subday_interval = 5 , @active_start_date = 0 , @active_end_date = 0 , @active_start_time_of_day = 500 , @active_end_time_of_day = 235959 Here is the step that runs in the agent job: Step Name: Run agent. Type: Replication Snapshot Command: -Publisher [WCDBS02] -PublisherDB [TaxDB] -Distributor [WCDBS02] -Publication [TaxDB] -ReplicationType 2 -DistributorSecurityMode 1 This appears to be running the Replication Snapshot Agent Utility. There is no mention on that link about dropping and recreating system conflict tables, nor is there any flag that can be set to alter this behavior.

  Read the article

• Importing Excel spreadsheet data into existing Access DB

  - by Keeb13r

  I've designed an Access 2003 DB with 3 tables: APPLICATIONS, SERVERS, and INSTALLATIONS. Records in the APPLICATIONS and SERVERS tables are uniquely identified by a synthetic primary key (in Access, an "auto number"). The INSTALLATIONS table is essentially a mapping table between APPLICATIONS and SERVERS: it's a list of records of which applications are installed on which servers. A record in the INSTALLATIONS table is also identified by a synthetic primary key, and it consists of an APPLICATION_ID and SERVER_ID for the records in their respective tables. I have an Excel 2003 spreadsheet I would like to import into this database, but it's proving difficult. The spreadsheet is made up of several tabs/worksheets, each one representing a server with its own listing of installed applications. I'm not sure how to proceed with an import - the "Get External Data -- Import" feature in Access has an import "In an Existing Table" option, but it's greyed out. I'm also unsure how I build the relationships between applications and servers for importing records into the INSTALLATIONS table. I had previously fooled around with adding some security to the Access DB file. I think I removed everything but perhaps I didn't and that's causing the problem? Some sample data from the Excel spreadsheet: SERVER101 * Adobe Reader 9 * BMC Remedy User 7.0 * HostExplorer 2008 * Microsoft Office 2003 * Microsoft Office 2007 * Notepad++ SERVER102 * Adobe Reader 9 * DameWare Mini Remote Control * Microsoft Office 2003 * Microsoft .NET Framework 3.5 SP1 * Oracle 9.2 SERVER103 * AWDView * EXTRA! Personal Client 32-bit * Microsoft Office 2003 * Microsoft .NET Framework 3.5 SP1 * Snagit 9.1 * WinZip 12.1 The Access DB design is very simple: APPLICATION * APPLICATION_ID (autonumber) * APPLICATION_NAME (varchar) SERVER * SERVER_ID (autonumber) * SERVER_NAME (varchar) INSTALLATION * INSTALLATION_ID (autonumber) * APPLICATION_ID (number) * SERVER_ID (number)

  Read the article

• Flexible forms and supporting database structure

  - by sunwukung

  I have been tasked with creating an application that allows administrators to alter the content of the user input form (i.e. add arbitrary fields) - the contents of which get stored in a database. Think Modx/Wordpress/Expression Engine template variables. The approach I've been looking at is implementing concrete tables where the specification is consistent (i.e. user profiles, user content etc) and some generic field data tables (i.e. text, boolean) to store non-specific values. Forms (and model fields) would be generated by first querying the tables and retrieving the relevant columns - although I've yet to think about how I would setup validation. I've taken a look at this problem, and it seems to be indicating an EAV type approach - which, from my brief research - looks like it could be a greater burden than the blessings it's flexibility would bring. I've read a couple of posts here, however, which suggest this is a dangerous route: How to design a generic database whose layout may change over time? Dynamic Database Schema I'd appreciate some advice on this matter if anyone has some to give regards SWK

  Read the article

• Multiple "ObjectChangeTracker" getting created, can it be avoided?

  - by user555937

  Hi, We are working on a POC where we have following architecture (MVVM), WPF(Client) + WCF + Model(DataAccess)+ ADO.Net Entity Framework 4.0 (with SQL Server 2008 R2 as DB) All are different projects. In the DataAccess layer we have created different Entity Models(edmx) based on the functionality. The tables under perticular flow are grouped and created different entity models. We are using self tracking entities to and fro to communicate with the WPF client through wcf service. For Single model everything works fine. But when we created a Multiple models then few issues started coming. Mutliple models have few duplicate tables/entities. Two probels are, 1) When we try to access entities from different models mutiple objects "ObjectChangeTracker" are getting created. E.g. CompanyModel(edmx) - Company(Entity) - ObjectChangeTracker, ObjectState ProductModel(edmx) - Customer(Entity) - ObjectChangeTracker1, ObjectState1 OrderModel(edmx) - Oder(Entity) - ObjectChangeTracker2, ObjectState2 Is there any way to avoid this? 2) There are few tables which shared across the Models, E.g. Company(Entity) is used in All above mdoels. During compile time it does not thow any error. But run time It gives error saying "Schema specified is not valid. Errors: The mapping of CLR type to EDM type is ambiguous because multiple CLR types match the EDM type "Company"".. To resolve this, we renamed the entities with some prefix to make them Unique. Is there any other way we can resolve this without changing the name of the entity in the same assembly? Thanks in advance and appreciate if anyone has approach for these issues. Thanks, Kiran

  Read the article

• How can I determine when an InnoDB table was last changed?

  - by David M

  I've had success in the past storing the (heavily) processed results of a database query in memcached, using the last update time of the underlying tables(s) as part of the cache key. For MyISAM tables, that last changed time is available in SHOW TABLE STATUS. Unfortunately, that's usually NULL for InnoDB tables. In MySQL 4.1, the ctime for an InnoDB in its SHOW TABLE STATUS line was usually its actual last update time, but that doesn't seem to be true for MySQL 5.1. There is a DATETIME field in the table, but it only shows when a row has been modified - it cannot show the deletion time of a row that's not there anymore! So, I really cannot use MAX(update_time). Here's the really tricky part. I have a number of replicas that I do reads from. Can I figure out the state of the table that doesn't rely on when the changes have actually been applied? My conclusion after working on this for a while is that it's not going to be possible to get this information as cheaply as I'd like. I'm probably going to cache data until the time that I expect the table to change (it's updated once a day), and let the query cache help out where it can.

  Read the article

• Does Microsoft Access use the PK fields for anything?

  - by chrismay

  Ok this is going to sound strange, but I have inherited an app that is an Access front end with a SQL Server backend. I am in the process of writing a new front end for it, but... we need to continue using the access front end for a while even after we deploy my new front end for reasons I won't go into. So both the existing Access app and my new app will need to be able to access and work with the data. The problem is the database design is a nightmare. For example some simple parent-child table relationships have like 4 and 5 part composite primary keys. I would REALLY like to remove these PKs and replace them with unique constraints or whatever, and add a new column to each of these tables called ID that is just an identity. If I change the PK and FKs on these tables to more managable fields, will the Access app have problems? What I mean is, does access use the meta data from the tables (PK and FK info) in such a way that it would break the app to change these?

  Read the article

• What should I use to increase performance. View/Query/Temporary Table

  - by Shantanu Gupta

  I want to know the performance of using Views, Temp Tables and Direct Queries Usage in a Stored Procedure. I have a table that gets created every time when a trigger gets fired. I know this trigger will be fired very rare and only once at the time of setup. Now I have to use that created table from triggers at many places for fetching data and I confirms it that no one make any changes in that table. i.e ReadOnly Table. I have to use this tables data along with multiple tables to join and fetch result for further queries say select * from triggertable By Using temp table select ... into #tx from triggertable join t2 join t3 and so on select a,b, c from #tx --do something select d,e,f from #tx ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. By Using Views create view viewname ( select ... from triggertable join t2 join t3 and so on ) select a,b, c from viewname --do something select d,e,f from viewname ---do somethign --and so on --around 6-7 queries in a row in a stored procedure. This View can be used in other places as well. So I will be creating at database rather than at sp By Using Direct Query select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something select a,b, c from select ... into #tx from triggertable join t2 join t3 join ... --do something . . --and so on --around 6-7 queries in a row in a stored procedure. Now I can create a view/temporary table/ directly query usage in all upcoming queries. What would be the best to use in this case.

  Read the article

• Shaping EF LINQ Query Results Using Multi-Table Includes

  - by sisdog

  I have a simple LINQ EF query below using the method syntax. I'm using my Include statement to join four tables: Event and Doc are the two main tables, EventDoc is a many-to-many link table, and DocUsage is a lookup table. My challenge is that I'd like to shape my results by only selecting specific columns from each of the four tables. But, the compiler is giving a compiler is giving me the following error: 'System.Data.Objects.DataClasses.EntityCollection does not contain a definition for "Doc' and no extension method 'Doc' accepting a first argument of type 'System.Data.Objects.DataClasses.EntityCollection' could be found. I'm sure this is something easy but I'm not figuring it out. I haven't been able to find an example of someone using the multi-table include but also shaping the projection. Thx,Mark var qry= context.Event .Include("EventDoc.Doc.DocUsage") .Select(n => new { n.EventDate, n.EventDoc.Doc.Filename, //<=COMPILER ERROR HERE n.EventDoc.Doc.DocUsage.Usage }) .ToList(); EventDoc ed; Doc d = ed.Doc; //<=NO COMPILER ERROR SO I KNOW MY MODEL'S CORRECT DocUsage du = d.DocUsage;

  Read the article

< Previous Page | 92 93 94 95 96 97 98 99 100 101 102 103  | Next Page >