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Asked: 2026-05-21T11:04:02+00:00

I’m brand new to SQL and I’m trying to understand the following script. could

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I’m brand new to SQL and I’m trying to understand the following script.
could someone break this down for me?

ErrorHandler:   
IF @@ERROR <> 0
BEGIN
ROLLBACK TRANSACTION
RAISERROR('Error occurred in script to update version: transaction rolled back', 182, 4)
END
ELSE
COMMIT

I have knowledge of Java, so I understand for loops.
It’s the SQL syntax that I need help with.

  1. For example, what does the double @ symbol represent?
  2. ROLLBACK TRANSACTION – these are SQL reserved keywords?
  3. What does ELSE COMMIT mean?

Thank you,
Ray

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1 Answer

  1. Editorial Team

    The stucture of the block is as follows:

    IF @@ERROR <> 0 
BEGIN 
  ROLLBACK TRANSACTION 
  RAISERROR('Error occurred in script to update version: transaction rolled back',  182, 4) 
END 
ELSE 
  COMMIT

    So this is a basic condition written in t-sql (no relation with java :)).
    The BEGIN and END tokens are just delimiters, and are used just like { and } in java – that’s why they are used in the IF branch (two commands) and are not used in the else branch (a single command – not mandatory)

    The @@Error (and other variables begining with @@, like @@ROWCOUNT) are system variables. @@Error specifically contains the last error code given by a command, and it is checked in the snippet to see if everything went OK.

    If there are errors, two actions are taken
    – a ROLLBACK TRANSACTION command is issued, reversing all changes made to the database (since the last BEGIN TRANSACTION)
    – an error is raised no notify the caller of the abnormal termination of the code.

    Here the constants (182 and 4) are used for the parameters of the RaiseError call @severity and @state. I suspect that the 182 is a typo, because @severity should be a number in the 0-25 range, and (by convention) 18 is used for a “high severity user error”. The @state param is just some data you can add to the call, to help distinguish between multiple error messages.

    If there are no errors, a single COMMIT TRANSACTION is issued, that makes all changes (since the last BEGIN TRANSACTION) permanent and available to all other users of the data.

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