借助以下 MySQL 查询，我们可以获得上个月的第一天 -
mysql> SELECT DATE_FORMAT(CURDATE() - INTERVAL 1 MONTH,'%Y-%m-01') AS 'FIRST DAY OF PREVOIUS MONTH'; +-----------------------------+ | FIRST DAY OF PREVOIUS MONTH | +-----------------------------+ | 2017-09-01 | +-----------------------------+ 1 row in set (0.00 sec)
