Question

Do u think there is a better way to write a transaction in t-sql? Is there a better approach that improves maintainability and performance of the application that uses this transaction?

-- Description: Insert email Receiver under specified subject
-- =============================================
ALTER PROCEDURE [Contact].[Receiver_stpInsert]
    @First_Name nvarchar(30),
    @Last_Name nvarchar(30),
    @Email varchar(60),
    @Subject_Id int
AS
BEGIN   
    SET NOCOUNT ON;

    DECLARE @error_num int;


    BEGIN TRANSACTION 

    INSERT INTO Contact.Receiver(First_Name, Last_Name, Email) VALUES(@First_Name, @Last_Name, @Email); 

    SET @error_num = @@ERROR;
    IF (@error_num <> 0)
        BEGIN
            ROLLBACK;
            RETURN;
        END

    DECLARE @rec_record_id int;
    SET @rec_record_id = (SELECT Record_Id FROM Contact.Receiver WHERE Email = @Email);

    SET @error_num = @@ERROR;
    IF (@error_num <> 0)
        BEGIN
            ROLLBACK;
            RETURN;
        END

    INSERT INTO Contact.Receiver_Subject(Receiver_Id, Subject_Id) VALUES(@rec_record_id, @Subject_Id);

    SET @error_num = @@ERROR;
    IF (@error_num <> 0)
        BEGIN
            ROLLBACK;
            RETURN;
        END

    SET @error_num = @@ERROR;
    IF (@error_num <> 0)
        BEGIN
            ROLLBACK;
            RETURN;
        END
    ELSE
        BEGIN   
            Commit;

        END

END

Answer 1

If you’re using SQL 2005 or later, you can use the TRY…CATCH block, like this:

BEGIN TRY
    BEGIN TRANSACTION;

    INSERT INTO Contact.Receiver(First_Name, Last_Name, Email) VALUES (@First_Name, @Last_Name, @Email); 
    ... other inserts etc 
    ...
    COMMIT TRANSACTION;
END TRY
BEGIN CATCH
    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH;

This way, you don’t keep repeating the same blocks of code checking @@ERROR. If you want to know what error occurred, in the BEGIN CATCH block you can get various bits of info:

• ERROR_NUMBER() returns the number of the error.
• ERROR_SEVERITY() returns the severity.
• ERROR_STATE() returns the error state number.
• ERROR_PROCEDURE() returns the name of the stored procedure or trigger
  where the error occurred.
• ERROR_LINE() returns the line number inside the routine that caused the
  error.
• ERROR_MESSAGE() returns the complete text of the error message. The text
  includes the values supplied for any
  substitutable parameters, such as
  lengths, object names, or times.