麻烦高人帮解释下这两条SQL语句的查询结果的数量为什么不一致?请说明理由selectdistincta.useridasuseridfrombzddzgamelog.ddzlogcreateuser201305aleftjoinbzddzpoker.pokeruserinfobona.userid=b.userIdwherea

Question

麻烦高人帮解释下这两条SQL语句的查询结果的数量为什么不一致?请说明理由
select distinct a.userid as userid from bz_ddzgamelog.ddz_log_createuser_201305 a left join bz_ddzpoker.poker_user_info b on a.userid=b.userId where a.adddatetime between '2013-05-01 00:00:00' and '2013-05-01 23:59:59' and b.qudaohao like '%';
select distinct a.userid as userid from bz_ddzgamelog.ddz_log_createuser_201305 a left join bz_ddzpoker.poker_user_info b on a.userid=b.userId where a.adddatetime between '2013-05-01 00:00:00' and '2013-05-01 23:59:59';

Answer 1

很明显问题是出现在and b.qudaohao like '%'这个条件上啊.你可以试试直接查询poker_user_info表,试试加与不加这个条件是否有区别.如果有区别就说明你的qudaohao这个字段里的内容有问题,如有没有区别就把这个条件放在第二个查询的WHERE后面,然后再用 between这个条件