小编SEa*_*986的帖子

我正在调试由其他人创建的报告，它具有以下加入条件。（我已根据自己的喜好进行了布局，并对表名进行了匿名化处理）

SELECT  --columns
FROM    Table1
        JOIN Table2
        JOIN Table3
            ON Table2.pred = Table3.pred
        JOIN Table4
            ON Table2.pred = Table4.pred
        JOIN Table5
            ON Table2.pred = Table5.pred AND Table2.pred = Table5.pred AND Table3.pred = Table5.pred
        JOIN Table6
            ON Table3.pred = Table6.pred
            ON Table1.pred = Table5.pred AND Table1.pred = Table5.pred
        LEFT JOIN Table7
            ON Table5.pred = Table7.pred AND Table5.pred = Table7.pred
        LEFT JOIN Table7 AS Table7_1
            ON Table5.pred = Table7_1.pred AND Table5.pred = Table7_1.pred
WHERE   --conditions

我感到困惑的是，没有将 Table1 与表 2 关联的联接，并且在联接到表 6 之后有两个 …