Question

I have a customer table in sqlserver which contains a rowversion field and I am incrementing it everytime I update the record,
I just have to check with

if(Customer.rowversion=@roeversion ) where customerID=@customerID

execute the update.

else RAISERROR('Update cannot be executed. There is a row version conflict.', 16, 1)

So have to now pass an out param from my c# code and return the error value. and also
– Get the Error Code for the statement just executed.

SELECT @ErrorCode=@@ERROR

So how should I return the value from SQLSERVER update query into my c# code so that I can display the message.

Answer 1

If you do not already, you should have your database code in a stored procedure. The stored procedure would look something like:

CREATE PROCEDURE s_my_procedure
  @RowVersion    int ,
  @CustomerID    int ,
  ... additional fields here
  @ErrorCode     INT OUTPUT
AS
  IF EXISTS(SELECT 1
              FROM Customer
             WHERE RowVersion = @RowVersion
               AND CustomerID = @CustomerID)
    BEGIN
      UPDATE Customer
         SET ...
       WHERE RowVersion = @RowVersion
         AND CustomerID = @CustomerID

      SET @ErrorCode = 0
    END 
  ELSE
    BEGIN
      SET @ErrorCode = 1234 -- Something meaningful to your app
    END

You should try to avoid raising errors whenever possible.

Then, assuming you have a stored procedure executed by a command:

cmd.ExecuteNonQuery();

int ErrorCode = 0;

// Note that if you are not sure about your sp, you should test this for dbnull.value first
ErrorCode = Convert.ToInt32(cmd.Parameters["@ErrorCode"].Value);