非字母和非 0 开头按顺序生成一个不重复的 id
select case when max(id) is null then '10000001' else max(id)+1 end as id from student;
字母开头按顺序生成一个不重复的 id
select case when max(id) is null then 'S10000001' else CONCAT('S',SUBSTRING(max(id),2)+1) end as id from student;
来源: http://www.bubuko.com/infodetail-2723258.html