MySQL syntax error for ON DUPLICATE KEY UPDATE

[bradcathey]

Fellow Monasterians,

I'm new to the INSERT ... ON DUPLICATE KEY UPDATE concept and now have been staring at this for an hour and not seeing the problem. Here's the code:

my $stmt = 'INSERT INTO contact_form (' . join(',', keys %sql) . ') VA
+LUES (' . join(',', ('?') x keys %sql) . ') ON DUPLICATE KEY UPDATE '
+. join(' = ?, ', keys %sql) . ' = ?';

Data::Dumper gives me:

$VAR1 = 'INSERT INTO contact_form (more_info,city,name,address,comment
+s) VALUES (?,?,?,?,?) ON DUPLICATE KEY UPDATE more_info = ?, city = ?
+, name = ?, address = ?, comments = ?';

Run-time error message

...for the right syntax to use near ' city = , name = , address = , co
+mments ='

What am I missing? (BTW, it works fine if I leave off the

ON DUPLICATE KEY UPDATE '
+. join(' = ?, ', keys %sql) . ' = ?'

)