Exception binding variables with cx_Oracle in python

Question

Okay, so I'm connected to an oracle database in python 2.7 and cx_Oracle 5.1 compiled against the instant client 11.2. I've got a cursor to the database and running SQL is not an issue, except this:

    cursor.execute('ALTER TRIGGER :schema_trigger_name DISABLE',
                     schema_trigger_name='test.test_trigger')

or

    cursor.prepare('ALTER TRIGGER :schema_trigger_name DISABLE')
    cursor.execute(None,{'schema_trigger_name': 'test.test_trigger'})

both result in an error from oracle:

    Traceback (most recent call last):
      File "connect.py", line 257, in 
        cursor.execute('ALTER TRIGGER :schema_trigger_name DISABLE',
                    schema_trigger_name='test.test_trigger')
    cx_Oracle.DatabaseError: ORA-01036: illegal variable name/number

While running:

    cursor.execute('ALTER TRIGGER test.test_trigger DISABLE')

works perfectly. What's the issue with binding that variable?

Answer 1

In your example test.test_trigger is not a variable but an object. You can only bind variables (that can be replaced by a value).

The query you are trying to run would be logically equivalent to:

ALTER TRIGGER 'test.test_trigger' DISABLE

Binding in this case won't work, you will have to build the query dynamically.

Answer 2

You normally can't bind an object name in Oracle. For variables it'll work but not for trigger_names, table_names etc.