当表中已经存在某条数据 现在想要插入一条新的覆盖他 可以 update 修改它 可以 delete 删除再添加 可以 replace 替代它

# 方法一
# delete from examination_info where exam_id = 9003;
# insert into examination_info(exam_id, tag, difficulty, duration, release_time) 
#     values(9003, 'SQL', 'hard', 90, '2021-01-01 00:00:00')
# 方法二    
replace into examination_info() values(null, 9003, 'SQL', 'hard', 90, '2021-01-01 00:00:00')