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POGetting return values from a MySQL stored procedure in Python, using MySQLdb
 

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  1. POGetting return values from a MySQL stored procedure in Python, using MySQLdb
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    <p>I've got a stored procedure in a MySQL database that simply updates a date column and returns the previous date. If I call this stored procedure from the MySQL client, it works fine, but when I try to call the stored procedure from Python using MySQLdb I can't seem to get it to give me the return value.</p> <p>Here's the code to the stored procedure:</p> <pre><code>CREATE PROCEDURE test_stuff.get_lastpoll() BEGIN DECLARE POLLTIME TIMESTAMP DEFAULT NULL; START TRANSACTION; SELECT poll_date_time FROM test_stuff.poll_table LIMIT 1 INTO POLLTIME FOR UPDATE; IF POLLTIME IS NULL THEN INSERT INTO test_stuff.poll_table (poll_date_time) VALUES ( UTC_TIMESTAMP() ); COMMIT; SELECT NULL as POLL_DATE_TIME; ELSE UPDATE test_stuff.poll_table SET poll_date_time = UTC_TIMESTAMP(); COMMIT; SELECT DATE_FORMAT(POLLTIME, '%Y-%m-%d %H:%i:%s') as POLL_DATE_TIME; END IF; END </code></pre> <p>The code I'm using to try to call the stored procedure is similar to this:</p> <pre><code>#!/usr/bin/python import sys import MySQLdb try: mysql = MySQLdb.connect(user=User,passwd=Passwd,db="test_stuff") mysql_cursor = mysql.cursor() results=mysql_cursor.callproc( "get_lastpoll", () ) print results mysql_cursor.close() mysql.close() except MySQLdb.Error, e: print "MySQL Error %d: %s" % ( e.args[0], e.args[1] ) sys.exit(1) </code></pre> <p>I know that you can do IN and OUT parameters, but from what I can determine from the MySQLdb documentation, this isn't possible with MySQLdb. Does anyone have any clue how I could get the results of the stored procedure?</p> <p>If I run it from a SQL tool, here's the output:</p> <pre><code>POLL_DATE_TIME ------------------- 2009-02-18 22:27:07 </code></pre> <p>If I run the Python script, it returns back an empty set, like this:</p> <pre><code>() </code></pre>
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