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    <p>If you're using ASP.Net, option A is your friend.</p> <p>Create a new connection for each request, Dispose()-ing when the request is complete. Ensure that you use <strong>identical</strong> connect strings. The connections will (by default) remain open and available through a connection pool.</p> <p>See <a href="http://msdn.microsoft.com/en-us/library/8xx3tyca.aspx" rel="nofollow">http://msdn.microsoft.com/en-us/library/8xx3tyca.aspx</a> for more information on connection pooling.</p> <p>You pretty much have to do it this way in a web server so you don't have concurrency issues anyway. Everything needs to be thread-safe (you've got no idea how many concurrent worker threads are executing in your app).</p> <p>[edited to add example code]</p> <p>As an example, here's what I would consider to be a typical method to execute a stored procedure. This comes from a custom code generator I wrote &mdash; handwritten code will likely look a little different &mdash; but it should suffice to get the point across:</p> <pre><code>public int Exec( int? @iPatientID ) { using ( SqlConnection conn = new SqlConnection( this.ConnectString ) ) using ( SqlCommand cmd = conn.CreateCommand() ) using ( SqlDataAdapter sda = new SqlDataAdapter( cmd ) ) { cmd.CommandText = STORED_PROCEDURE_NAME ; cmd.CommandType = CommandType.StoredProcedure ; if ( this.TimeoutInSeconds.HasValue ) { cmd.CommandTimeout = this.TimeoutInSeconds.Value ; } // // 1. @iPatientID // SqlParameter p1 = new SqlParameter( @"@iPatientID" , SqlDbType.Int ) ; if ( @iPatientID == null ) { p1.Value = System.DBNull.Value ; } else { p1.Value = @iPatientID ; } cmd.Parameters.Add( p1 ) ; // add return code parameter SqlParameter pReturnCode = new SqlParameter() ; pReturnCode.SqlDbType = System.Data.SqlDbType.Int ; pReturnCode.Direction = System.Data.ParameterDirection.ReturnValue ; cmd.Parameters.Add( pReturnCode ) ; DataSet ds = new DataSet() ; conn.Open() ; sda.Fill( ds ) ; conn.Close() ; this.ResultSet = ( ds.Tables.Count &gt; 0 ? ds.Tables[0] : null ) ; this.ReturnCode = (int) pReturnCode.Value ; } return this.ReturnCode ; } </code></pre>
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    1. POBest way to deal with DB Connection in the DAL - create or pass?
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    1. USNicholas Carey
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    1. COYes, its an ASP.Net Website. Thanks for the link and the answer. But I dont understand how passing the connection can be a concurrency issue?
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      1. USmagnattic
    2. CO@atticae: it would only become a concurrency issue if the connection object ends up getting used by multiple threads. Whether this happens would depend on how your code is structured, but it's far less likely to happen accidentally if you're creating and disposing the connection within the context of a data-access method.
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    3. COThe only time that you might want to pass the SqlConnection around would be if multiple DAL methods needed to participate in the same SqlTransaction. This is probably best avoided.
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      1. USuncle brad
 

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