query: SELECT date_to FROM Project_Staff ORDER BY date_to DESC LIMIT 1
question: What is the last date of the staff leaving the projects?
query_toks: SELECT date_to FROM Project_Staff ORDER BY date_to DESC LIMIT 1
query_toks_no_value: select date_to from project_staff order by date_to desc limit value
question_toks: What is the last date of the staff leaving the projects?