Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_25390694_2 (production_code VARCHAR, writer VARCHAR)

### Question ###
What was the production code of the episode written by Brendan Cowell?

### Accurate SQL ###

SELECT production_code FROM table_25390694_2 WHERE writer = "Brendan Cowell"