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 journal_committee ( editor_id number, journal_id number, work_type text )
TABLE: CREATE TABLE journal ( journal_id number, date text, theme text, sales number )
TABLE: CREATE TABLE editor ( editor_id number, name text, age number )

### Question ###
What is the average sales of the journals that have an editor whose work type is 'Photo'?

### Accurate SQL ###

SELECT AVG(T1.sales) FROM journal AS T1 JOIN journal_committee AS T2 ON T1.journal_id = T2.journal_id WHERE T2.work_type = 'Photo'