Catching Specific Exception question...

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Catching Specific Exception question...

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StarkMike	StarkMike posted 17 Years Ago Topic Details Share Topic
Group: Forum Members Posts: 436, Visits: 944	How would I catch a specific exception? For instance I have a table with a compound primary key... the primary key is not an auto increment but I dont want to allow duplicates to be inserted. When I try to insert a duplicate it throws an exception, naturally. I am able to trap the SQLException but I'm not sure how to catch that specific 'Violation of PRIMARY KEY constraint'... Should I query the table before I attempt the insert instead of trying to catch the exception?
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Trent Taylor	Trent Taylor posted 17 Years Ago Post Details Share Post
Group: StrataFrame Developers Posts: 6.6K, Visits: 6.9K	Well, you cannot override the exception since the error is actually happening on the SQL Server itself and you will never be able to work around the constraint. We generally test for the uniquness of a value using a scalar command within the CheckRulesOnCurrentRow event. Public Function CheckForDuplicate(ByVal MyPassedTestValue As String) As Integer Dim loCommand As New SQLCOmmand() Dim lnPK As Integer '-- Skip the current record IF Me.Count > 0 Then lnPK = Me.PrimaryKeyField Else lnPK = -1 End If '-- Build the command text loCommand.CommandText = "SELECT COUNT(*) FROM MyTable WHERE MyPrimaryKeyField != @MyPrimaryKeyField And MyTestField = @MyTestField" '-- Create the parms loCommand.Parameters.Add("@MyPrimaryKeyField",SqlDataType.Int) loCommand.Parameters.Add("@MyTestField",SqlDataType.VarChar) '-- Set the parms loCommand.Parameters("@MyPrimaryKeyField").Value = lnPK loCommand.Parameters("@MyTestField").Value = MyPassedTestValue '-- Return the results Return CType(Me.ExecuteScalar(loCommand), Integer) End Sub
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