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VB.net SQL make sure only single value returned

Posted on 2014-03-12
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Last Modified: 2014-03-13
Hi. I am using the following code to pull a single result from a SQL table.
I need a way to check if the result returns more than one value first.
Is there a way to build that into this code? If not what code would I need
to run first to see if there is a single value returned for this SQL statement

                Dim connection As New SqlConnection(oConnectionString)
                Dim cmd As New SqlCommand(sSQL, connection)
                connection.Open()
                oResult = cmd.ExecuteScalar.ToString
                If IsDBNull(oResult) = True Then
                    Get_Value = "Null"
                Else
                    Get_Value = oResult
                End If
                connection.Close()
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Question by:Murray Brown
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AndyAinscow earned 500 total points
ID: 39925689
Assuming your SQL command doesn't have something such TOP 1 (to force maximum one row being returned in the query) you would need to use a reader:
http://msdn.microsoft.com/en-us/library/9kcbe65k%28v=vs.110%29.aspx

Instead of the ExecuteScalar you would use ExecuteReader.  Store the result from the first returned row if any and then check if there was a second row to see if more than one row was returned.
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Author Closing Comment

by:Murray Brown
ID: 39925782
Thanks very much
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