获取当月第一天：

DATE_ADD(curdate(),interval -day(curdate())+1 day))

ADDDATE(NOW(), INTERVAL -#{start} MONTH)

%Y-%m-%d %T

Oracle:

(SYSDATE- STR_TO_DATE(b.CREATE_TM, '%Y-%m-%d %T'))*24*60)

转换为：
MySQL:

(TO_DAYS(NOW()) - TO_DAYS(STR_TO_DATE("2022-11-26 11:11:11","%Y-%m-%d %T")))*24*60