获取 id 值

Question

     
     id               name            info
-------------------------------------------------
      1                张三           20;30
      2                李四           40;60    如何 用 根据 info 字段 的  '20', 查询出 这条记录 的  id  
    谢谢

Answer 1

select id from tbname where instr(info,20) 

Answer 2

select * from table1 where find_in_set(20,info)>0

Answer 3

select id from tbname where left(info,2)='20';