DECLARE EXIT HANDLER FOR SQLEXCEPTION

The DECLARE EXIT HANDLER FOR SQLEXCEPTION statement is used in MySQL to define an exception handler that will be executed when an exception is thrown in a stored procedure or function. This statement is followed by the code block that will be executed when an exception occurs.

The purpose of this statement is to handle exceptions in a controlled way, allowing developers to define how their application should respond to specific error conditions. For example, if a stored procedure encounters an error while processing data, the exception handler can be used to log the error, roll back the transaction, or take any other desired action.

Here is an example of how to use the DECLARE EXIT HANDLER FOR SQLEXCEPTION statement:

DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
  -- Code block to handle the exception goes here
END;

Within the code block, you can use any valid MySQL statements to handle the exception. You can also access information about the exception using the SQLSTATE and SQLERRM functions.

It is important to note that if an exception is not handled by an explicit DECLARE EXIT HANDLER statement, the default behavior is to terminate the stored procedure or function and return an error to the client.