zoukankan      html  css  js  c++  java
  • mysql in 子查询 效率慢,对比

     desc SELECT id,detail,groupId from hs_knowledge_point where groupId in (
        SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        UNION all
        SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    )
    UNION ALL
    SELECT id,detail,groupId from hs_knowledge_point_commit where groupId in (
        SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        UNION all
        SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
    )
    View Code
    SELECT id,detail,groupId from hs_knowledge_point where groupId in (
        select groupId from (
            SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
            UNION all
            SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        ) tmp
    )
    UNION ALL
    SELECT id,detail,groupId from hs_knowledge_point_commit where groupId in (
        select groupId from (
            SELECT groupId from hs_knowledge_point where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
            UNION all
            SELECT groupId from hs_knowledge_point_commit where groupId>0 GROUP BY groupId HAVING COUNT(groupId) > 1 
        ) tmp
    )
    View Code

  • 相关阅读:
    组合数取模的题……
    对组合数取模
    n!(n的阶乘)
    八、元素绑定
    七、Application类
    RC振荡电路
    运算放大器工作原理
    No
    合并查询结果
    连接查询
  • 原文地址:https://www.cnblogs.com/shixm/p/7300937.html
Copyright © 2011-2022 走看看