tianshi1017的专栏

select  a.id as id,                     count(distinct b.id) as bid,                    count(distinct c.id) as cid     from  user a left join user_role b  on a.userId = b.userId     left join

ibatis 配置文件中取值有两种：#和$如果传值为userName="zhangsan"#userName# , ibatis会自动在它的外面加上引号,结果是这样的:select * from user where user_name = 'zhangsan' ;$userName$ 则是把zhangsan作为字符串拼接到sql中,结果是这样的:select * from user