MySQL Stored Procedure Error Handling

I believe there is nothing currently available in MySQL that allows access to the SQLSTATE of the last executed statement within a MySQL stored procedure. This means that ... it is hard/impossible to derive the exact nature of the error.

Luckily that is not true.

SHOW ERRORS LIMIT 1   -- for SQL-state > 2
SHOW WARNINGS LIMIT 1 -- for SQL-state 1,2

Will show the last error or warning.

In order to prevent listing each and every error, you can handle a class of SQL-errors like so:

SQLWARNING is shorthand for the class of SQLSTATE values that begin with '01'.

NOT FOUND is shorthand for the class of SQLSTATE values that begin with '02'. This is relevant only within the context of cursors and is used to control what happens when a cursor reaches the end of a data set. If no more rows are available, a No Data condition occurs with SQLSTATE value 02000. To detect this condition, you can set up a handler for it (or for a NOT FOUND condition). An example is shown in Section 12.7.5, “Cursors”. This condition also occurs for SELECT ... INTO var_list statements that retrieve no rows.

SQLEXCEPTION is shorthand for the class of SQLSTATE values that do not begin with '00', '01', or '02'.

So to handle an exception, you need to only do:

DECLARE EXIT HANDLER FOR SQLSTATE SQLEXCEPTION .....;

Links:
http://dev.mysql.com/doc/refman/5.5/en/signal.html
http://dev.mysql.com/doc/refman/5.0/en/declare-handler.html

GET DIAGNOSTICS is available in 5.6.4

See http://dev.mysql.com/doc/refman/5.6/en/get-diagnostics.html