Comment 2 for bug 1288719

Original:
cr.execute('select * from ir_module_module where name=%s and state=%s', ('product_m2mcategories','installed'))

Will produce SQL statement:
select * from ir_module_module where name=product_m2mcategories and state=installed

Changed:
cr.execute("select * from ir_module_module where name='product_m2mcategories' and state='installed'")

Will produce SQL statement:
select * from ir_module_module where name='product_m2mcategories' and state='installed'

Comment:
The difference is that name='...' is a string in column name and name=product_m2mcategories is a column called product_m2mcategories compared to column name...