Database: financial (difficulty: simple)
Question: For the first client who opened his/her account in north Bohemia, what is his/her account ID?
SQL: SELECT T1.account_id FROM account AS T1 INNER JOIN district AS T2 ON T1.district_id = T2.district_id WHERE T2.A3 = 'north Bohemia' ORDER BY T1.date ASC LIMIT 1