Dev-Picayune

Okay, very weird problem today. I am not sure what to make of it… when using the latest version of MySQLdb (1.2.2.final.0) which is the version in Ubuntu 7.10 Gutsy, I am getting an “incomplete format” error when performing an executemany. My variables are presented as a list of dictionaries as I’m using named/mapped variables in the SQL statement. Using the exact same code with MySQLdb (1.2.1.final.2) is fine (the version in Ubuntu Feisty 7.04).

So for completeness sake, I have documented the scenario like this:

On a MySQL server, you just need a simple little table:

CREATE TABLE `test_table` (
`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`test_col_1` VARCHAR(20) NOT NULL,
`test_col_2` VARCHAR(20) NOT NULL,
PRIMARY KEY  (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=latin1

Then the Python code (obviously you’ll need to set the connection stuff appropriately):

import MySQLdb
 
print "-----------------------------------------------------"
print MySQLdb.version_info
print "-----------------------------------------------------"
 
sqlStringItems = """INSERT INTO test_table
(test_col_1,test_col_2)
VALUES
(%(test1)s, %(test2)s);"""
 
dtlDict = {'test1':'test value 1','test2':'test value 2'}
 
con = MySQLdb.connect(host="localhost",user="myuser",passwd="mypassword",db="test")
cur = con.cursor()
exitval = cur.executemany(sqlStringItems,[dtlDict])
 
print "exit value from executemany= " + str(exitval)
cur.close()

version (1, 2, 2, ‘final’, 0) yields:

ValueError: incomplete format

Whereas version (1, 2, 1, ‘final’, 2) works fine.

Also, doing the same thing, but with execute instead of executemany works fine (and of course taking the dict out of the list). So this seems to be purely an issue with executemany. Looking at the MySQLdb code, it’s obvious that between the two versions it was pretty radically changed.

I guess I need to report this as a bug, but I’m just finding it hard to believe that I didn’t do something wrong.

Update (2008-06-03)
Back in January, I reported this issue (1874176). Then in late April, Raphael Guillet submitted a possible fix. I haven’t spent much time looking at the right vs. wrong of the fix, but I have tried it and it appears to work. So for those looking, here’s the possible fix which as near as I can tell has still not been cut into the official version.

The change is in the cursors.py file. So you have to hunt that down wherever it is stored in your particular OS version and/or install.

Comment out lines 201 and 202:

        #e = m.end(1)
        #qv = m.group(1)

And then add right after that:

        e=len(query)
        qv = query[p:e]

I’ll try to continue to monitor this.