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POLINQ to SQL: Updating without Refresh when “UpdateCheck = Never”
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  1. POLINQ to SQL: Updating without Refresh when “UpdateCheck = Never”
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    copied!<p>I have an Account entity which has all fields in “UpdateCheck = Never” except one field. The “ModifiedTime” field uses “UpdateCheck=Always”. The intention is – concurrency check should be based on “ModifiedTime” column only. </p> <p>For the test purpose I am supplying the “ModifiedTime” value hard coded in C# code. So there is no need to fetch any value from database for concurrency. Still the code will update the database only if I call for the Refresh method. This seems strange. Any approach to avoid this?</p> <p>Refer: "Updating Without Querying" section in <a href="http://msdn.microsoft.com/en-us/library/bb386929.aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/bb386929.aspx</a></p> <p>Note: I am trying to avoid the SELECT statement by not using Refresh</p> <p>Generated SQL</p> <pre><code> SELECT [t0].[AccountNumber], [t0].[AccountType], [t0].[Duration], [t0].[DepositedAmount], [t0].[Prefernce], [t0].[Comment], [t0].[ModifiedTime] FROM [dbo].[Account] AS [t0] WHERE [t0].[AccountNumber] = @p0 -- @p0: Input Int (Size = -1; Prec = 0; Scale = 0) [1] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 4.0.30319.1 </code></pre> <p>Update Query</p> <pre><code>UPDATE [dbo].[Account] SET [AccountType] = @p2, [Duration] = @p3 WHERE ([AccountNumber] = @p0) AND ([ModifiedTime] = @p1) -- @p0: Input Int (Size = -1; Prec = 0; Scale = 0) [1] -- @p1: Input DateTime (Size = -1; Prec = 0; Scale = 0) [6/25/2012 5:08:32 PM] -- @p2: Input NChar (Size = 10; Prec = 0; Scale = 0) [SUCESS] -- @p3: Input Int (Size = -1; Prec = 0; Scale = 0) [2] -- Context: SqlProvider(Sql2008) Model: AttributedMetaModel Build: 4.0.30319.1 </code></pre> <p>Table Structure</p> <pre><code>CREATE TABLE [dbo].[Account]( [AccountNumber] [int] NOT NULL, [AccountType] [nchar](10) NOT NULL, [Duration] [int] NOT NULL, [DepositedAmount] [int] NULL, [Prefernce] [int] NULL, [Comment] [nvarchar](50) NULL, [ModifiedTime] [datetime] NOT NULL, CONSTRAINT [PK_Account] PRIMARY KEY CLUSTERED ( [AccountNumber] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY] ) ON [PRIMARY] </code></pre> <p>C# Code</p> <pre><code> public virtual void UpdateChangesByAttach(T entity) { if (Context.GetTable&lt;T&gt;().GetOriginalEntityState(entity) == null) { //If it is not already attached Context.GetTable&lt;T&gt;().Attach(entity); Context.Refresh(System.Data.Linq.RefreshMode.KeepCurrentValues, entity); } } public void UpdateAccount() { //Used value from previous select DateTime previousDateTime = new DateTime(2012, 6, 25, 17, 8, 32, 677); RepositoryLayer.Account accEntity = new RepositoryLayer.Account(); accEntity.AccountNumber = 1; accEntity.AccountType = "SUCESS"; accEntity.ModifiedTime = previousDateTime; accEntity.Duration = 2; accountRepository.UpdateChangesByAttach(accEntity); accountRepository.SubmitChanges(); } </code></pre> <p>Table Data</p> <p><img src="https://i.stack.imgur.com/RZV1K.png" alt="enter image description here"></p> <p>READING:</p> <ol> <li><p><a href="https://stackoverflow.com/questions/3301811/linq-to-sql-how-to-update-the-only-field-without-retrieving-whole-entity?lq=1">LINQ to SQL: how to update the only field without retrieving whole entity</a></p></li> <li><p><a href="https://stackoverflow.com/questions/399379/update-without-first-selecting-data-in-linq-2-sql">Update without first selecting data in LINQ 2 SQL?</a></p></li> <li><p><a href="https://stackoverflow.com/questions/1996911/update-select-in-linq-to-sql">UPDATE SELECT in LINQ to SQL</a></p></li> <li><p><a href="https://stackoverflow.com/questions/9385041/linq-to-sql-update-mulitple-rows">linq to sql update mulitple rows</a></p></li> <li><p><a href="https://stackoverflow.com/questions/11186813/default-values-of-c-sharp-variables-issue-in-linq-to-sql-update">Default Values (of C# variables) Issue in LINQ to SQL Update</a></p></li> </ol> <hr>
 

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