随着应用对高性能需求的增加,NoSQL逐渐在各大名企的系统架构中生根发芽。这里我们将为大家分享社交巨头新浪微博带来的Redis实践,首先我们看新浪微博 @启盼cobain的Redis实战经验分享: Tape is Dead,Disk is Tape,Flash is Disk,RAM Locality is King. — Jim Gray Redis…
表1-USERU 表2-DEVICE 关联查询统计数量sql
SELECT count(1) as count,a.ID,a.NAME
FROM USERU a left JOIN DEVICE b on a.ID b.USERID
group by a.ID,a.NAME HAVING count(1)>0关联查询统计数量结果(having 过滤数量大于0) 如果没有count统计
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