Question

Good afternoon everyone,

I am having an issue with a stored procedure inserting an incorrect value. Below is a summarization of my stored procedure …

set ANSI_NULLS ON set QUOTED_IDENTIFIER ON go CREATE PROCEDURE [dbo].[InsertDifferential]     @differential int = null AS     BEGIN TRY         BEGIN TRANSACTION             UPDATE                 DifferentialTable             SET                 differential = @differential         COMMIT     END TRY     BEGIN CATCH         IF @@TRANCOUNT > 0         ROLLBACK         DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int, @ErrorState INT         SELECT @ErrMsg = ERROR_MESSAGE(),                 @ErrSeverity = ERROR_SEVERITY(),                @ErrorState = ERROR_STATE();         RAISERROR(@ErrMsg, @ErrSeverity, @ErrorState);     END CATCH 

Below is the code I use to call the stored procedure …

SqlConnection dbEngine = new SqlConnection(connectionString); SqlCommand dbCmd = new SqlCommand('InsertDifferential', dbEngine); SqlDataAdapter dataAdapter = new SqlDataAdapter(dbCmd);  dbCmd.CommandType = CommandType.StoredProcedure;  if (myobject.differential.HasValue) { dbCmd.Parameters.AddWithValue('@differential', myobject.differential); } else { dbCmd.Parameters.AddWithValue('@differential', DBNull.Value); }  dbCmd.ExecuteNonQuery(); 

In the database table, the differential column is a nullable int with no default value.

The differential property of ‘myobject’ is an int? data type set to null by default.

The issue is when I run the stored procedure, the differential column winds up with a 0 in place. Even if ‘myobject.differential’ is null and I pass in the DBNull.Value the column still winds up with a 0 in place. I’ve tried not passing the @differential into the stored procedure and it still sets the column to 0.

I’ve tried a number of different solutions and nothing has worked.

Thank you in advance for any assistance,

Scott Vercuski

Answer 1

I believe that when you set the default value on a parameter like

@differential int = null 

You do not need to add it to your SQL Command.

Try the code with just this and do not include the else…

if (myobject.differential.HasValue) {     dbCmd.Parameters.AddWithValue('@differential', myobject.differential);  }