[英]Oracle outer join syntax
I have a query that looks like this: 我有一个查询,看起来像这样:
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(+)
I know (+) is old syntax for a join, but I am not sure what it is actually doing to this query. 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。 Could someone explain this and show this query without the (+) in the where statement, using more modern join syntax? 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 believe you want this: 我相信你想要这样:
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;
To be honest, the outer join is probably not necessary. 老实说,可能不需要外部联接。 Why would lf
have a cust_id
that is not valid? 为什么lf
的cust_id
无效? The only reasonable possibility is if the value is NULL
. 唯一合理的可能性是,如果该值为NULL
。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.