把查询到结果合并放在一行 JOIN非union

转载于 2016-01-08 21:49:00 发布 · 105 阅读

本文深入探讨了SQL查询优化策略，通过分析查询效率瓶颈并应用最佳实践，显著提升数据库性能。同时，介绍了大数据处理技术，包括分布式计算框架与数据仓库的构建，以应对大规模数据集的挑战。

select one.max,one.min,one.low sts,c.high ens,one.time from (

        select a.max max,a.min min,b.low low,a.time time,a.aid aid from

        (select max(price) max,min(price) min,time time,id aid from on_jiaoyi_into where sid=".$id."
        group by DATE_FORMAT(`time`,'%Y-%m-%d') ) a LEFT JOIN

        (select price low,id bid from on_jiaoyi_into where sid=".$id."
        group by DATE_FORMAT(`time`,'%Y-%m-%d')  
        order by time ) b on a.aid=b.bid 

        ) one LEFT JOIN

        (select price high,id cid from on_jiaoyi_into where sid=".$id."
        group by DATE_FORMAT(`time`,'%Y-%m-%d')  
        order by time desc) c on one.aid=c.cid