Database: book_publishing_company
Question: List all the titles and year to date sales by author who are not on contract.
SQL: SELECT T1.title_id, T1.ytd_sales FROM titles AS T1 INNER JOIN titleauthor AS T2 ON T1.title_id = T2.title_id INNER JOIN authors AS T3 ON T2.au_id = T3.au_id WHERE T3.contract = 0