Qual é a média de vendas dos jornais que têm um editor cujo tipo de trabalho é 'Foto'?
CREATE TABLE journal_committee (journal_ID VARCHAR, work_type VARCHAR); CREATE TABLE journal (sales INTEGER, journal_ID VARCHAR)
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'