Bug when passing a query to execute that is a psycopg2 SQL object

[zschumacher]

When you pass a SQL object from psycopg2.sql, we run into an unexpected error in the is_sql_dirty function. When we hit the line that tries to do sql.lower(), we may have passed in a SQL object, resulting in packages/cacheops/transaction.py", line 113, in is_sql_dirty sql = sql.lower() AttributeError: 'Composed' object has no attribute 'lower'

Perhaps it would be reasonable to add a block such as

if isinstance(sql.SQL):
    sql = sql.as_string(self.connection)

Would love other thoughts on this.

[Suor]

Can you create a test?

[zmaktr]

The issue still persists.

[Suor]

A test will help to move it.

[courcelm]

Hit the same issue while using django-bulk-load.