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 Staff (date_joined_staff VARCHAR, first_name VARCHAR, last_name VARCHAR)

### Question ###
When did the staff member with first name as Janessa and last name as Sawayn join the company?

### Accurate SQL ###

SELECT date_joined_staff FROM Staff WHERE first_name = "Janessa" AND last_name = "Sawayn"