2008年11月8日

连续 两个 LEFT JOIN LEFT JOIN

摘要： http://forums.devshed.com/mysql-help-4/how-to-avoid-using-inefficient-in-not-in-in-a-568063.html With appropriate indexes, this should be quite efficient enough:SELECT tb3.employee_name, (salary+bonu... 阅读全文

posted @ 2008-11-08 23:28 cy163 阅读(14321) 评论(0) 推荐(0) 编辑

MySQL 交集 实现方法

摘要： 1MySQL中如何实现以下SQL查询 (SELECT S.Name FROM STUDENT S, TRANSCRIPT T WHERE S.StudId = T.StudId AND T.CrsCode = 'CS305') INTERSECT (SELECT S.Name FROM STUDENT S, TRANSCRIPT T WHERE S.StudId = T.StudId AND T.... 阅读全文

posted @ 2008-11-08 23:05 cy163 阅读(7464) 评论(0) 推荐(0) 编辑

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