将子查询转化成连表查询问题
SELECT * FROM (SELECT a.video_name NAME,a.vid,a.pos,a.pic,a.definition,b.app_code,a.strength,a.ad_mark FROM access_app_video a
LEFT JOIN access_app b ON a.app_id=b.id WHERE tag_interest=2 AND app_id=1 AND a.ad_mark=1 AND a.status=0 ORDER BY ABS(tag_sex-16),ABS(tag_figure-10)) aa
ORDER BY aa.strength DESC LIMIT 0,12
该子查询如何改为连表查询
回复讨论(解决方案)
SELECT a.video_name NAME,a.vid,a.pos,a.pic,a.definition,b.app_code,a.strength,a.ad_mark FROM access_app_video a LEFT JOIN access_app b ON a.app_id=b.id WHERE tag_interest=2 AND app_id=1 AND a.ad_mark=1 AND a.status=0 ORDER BY a.strength, ABS(tag_sex-16),ABS(tag_figure-10) DESC LIMIT 0,12
感谢2楼回答,但是这样写,搜索出的结果和原结果是不同的,原sql的意思是先按照ABS(tag_sex-16),ABS(tag_figure-10)排序
之后再根据a.strength排序,2楼给的sql改变了排序规则。。
#2
该语句是不是不能使用连表查询?
最终的结果是按 a.strength 降序,当 a.strength 相同时 按 ABS(tag_sex-16),ABS(tag_figure-10) 升序
当然,当 ABS(tag_sex-16),ABS(tag_figure-10) 有多组相同值的时候,结果会略有不同
这也就是作者那样写的原因吧
5
是这样的,现在是想用orm去写sql,一直以为所有子查询都能用连表查询替代,才想把子查询改成连表查询,想了想,连表查询好像解决不了,只能继续这样写了

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