Handling multiple data sets in stored procedures from Perl

MySQL stored procedures can use SELECT statements in their body, returning a data set to the caller. The manual also explains that multiple data sets can be returned from such a stored procedure.
For example, assume you have this stored procedure:

CREATE PROCEDURE p1(x INT, y INT)
    DETERMINISTIC
    BEGIN
        SELECT 
            x ;
        SELECT 
            x AS first_param, 
            y AS second_param;
        SELECT 
            x, 
            y, 
            x + y AS sum_xy, 
            x * y AS prod_xy; 
        SELECT *  FROM t1;
    END

There are four SELECT statements, with different headers, and a variable number of rows returned.
Early versions of DBD::mysql could not handle multiple data sets. Actually, prior to version 3.0004 they could not even handle one dataset from a stored procedure. Starting with version 4.001, single and multiple datasets from SPs are handled gracefully.
The trick is to call $sth->more_results after retrieving each dataset.
See the complete example at Multiple data sets in MySQL stored procedures


For those interested, the MySQL Users Conference and Expo includes a BoF about DBD::mysql on April 24^th at 7:30pm.