MySQL last_insert_id() error

Hello everyone.

I have a connector that insert a row in an external mysql db that works correctly. Now, I wanted to extend such connector in order to return the id of the lastly inserted row (the mysql table has a auto_incremented field) which I want to save in a variable to use it for future editing within the same process (I do that in the output operation definition part of the connector). The groovy code looks like this: