- Returns the error text from the last fbsql function, or '' (the empty string) if no error occurred.

- Errors coming back from the fbsql database backend don't issue warnings. Instead, use fbsql_error() to retrieve the error text. Note that this function only returns the error text from the most recently executed fbsql function (not including fbsql_error() and fbsql_errno()), so if you want to use it, make sure you check the value before calling another fbsql function.