Oracle外连接语法 [英] Oracle outer join syntax

问题描述

我有一个如下查询:

select *
from find fsc,
        let lf,
        cust cus,
        STRIKE ist
WHERE   fsc.id = lf.id
AND     ist.ID_old = fsc.ID_old
AND     lf.cust_id = cus.cust_id(+)

我知道(+)是联接的旧语法，但是我不确定它对该查询的实际作用.有人可以解释一下，并使用更现代的连接语法在where语句中显示不带(+)的查询吗?

I know (+) is old syntax for a join, but I am not sure what it is actually doing to this query. Could someone explain this and show this query without the (+) in the where statement, using more modern join syntax?

推荐答案

我相信您想要这样做:

select *
from find fsc join
     let lf
     on fsc.id = lf.id join
     STRIKE ist
     on ist.ID_old = fsc.ID_old left join
     cust cus
     on lf.cust_id = cus.cust_id;

说实话，外部联接可能不是必需的.为什么lf的cust_id无效?唯一合理的可能性是值是否为NULL.

To be honest, the outer join is probably not necessary. Why would lf have a cust_id that is not valid? The only reasonable possibility is if the value is NULL.

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