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_30011_2 (reference VARCHAR, example VARCHAR)

### Question ###
What is every reference for the example of AF117?

### Accurate SQL ###

SELECT reference FROM table_30011_2 WHERE example = "AF117"