在 Oracle 中,关于语法——如何将 (+) 语法转换为现代常规 JOIN?
In Oracle, in regards to syntax - how do I convert the (+) syntax to modern conventional JOIN?
假设我有一个像这样的 FROM 子句:
FROM
apps.po_requisition_lines_all prl,
apps.po_requisition_headers_all prha,
po.po_req_distributions_all prda,
po.po_distributions_all pda,
po.po_headers_all pha
where 1=1
and prl.requisition_header_id= prha.requisition_header_id
and prl.requisition_line_id= prda.requisition_line_id
and prda.distribution_id= pda.req_distribution_id(+)
and pha.po_header_id(+)=pda.po_header_id
那么如果我们想使用普通的JOIN语法,那么这种类型的OUTER JOIN如何转换呢?谢谢!
在没有看到模式的情况下,我觉得很难,但这应该让你朝着正确的方向前进:
FROM apps.po_requisition_lines_all prl
INNER JOIN apps.po_requisition_headers_all prha ON prl.requisition_header_id = prha.requisition_header_id
INNER JOIN po.po_req_distributions_all prda ON prda.requisition_line_id = prl.requisition_line_id
LEFT JOIN po.po_distributions_all pda ON prda.distribution_id = pda.req_distribution_id
-- I note from the example provided that this is a right join
-- Without seeing the schema, it looks to me as though it should be left
-- As I say say, without seeing the schema, I probably shouldn't pass comment
RIGHT JOIN po.po_headers_all pha ON pha.po_header_id = pda.po_header_id;
对于 INNER JOIN
你可以只说 JOIN
虽然我认为明确地说 INNER
有助于提高可读性。我还注意到提供的示例有 WHERE 1=1
,这是多余的。
+是Outer Joins
的旧版本,与[=33不同=]+出现在等号之后或之前,但是现在建议使用Join
关键字而不是+
,关于+ 来了就签:
=之后:
select * from t1, t2
where t1.id=t2.id(+)
这意味着左外连接:
select * from t1
left outer join t2 on t1.id=t2.id
之前=:
select * from t1, t2
where t1.id(+)=t2.id
这意味着右外连接:
select * from t1
Right outer join t2 on t1.id=t2.id
没有+:
select * from t1, t2
where t1.id=t2.id
这意味着内连接:
select * from t1
join t2 on t1.id=t2.id
假设我有一个像这样的 FROM 子句:
FROM
apps.po_requisition_lines_all prl,
apps.po_requisition_headers_all prha,
po.po_req_distributions_all prda,
po.po_distributions_all pda,
po.po_headers_all pha
where 1=1
and prl.requisition_header_id= prha.requisition_header_id
and prl.requisition_line_id= prda.requisition_line_id
and prda.distribution_id= pda.req_distribution_id(+)
and pha.po_header_id(+)=pda.po_header_id
那么如果我们想使用普通的JOIN语法,那么这种类型的OUTER JOIN如何转换呢?谢谢!
在没有看到模式的情况下,我觉得很难,但这应该让你朝着正确的方向前进:
FROM apps.po_requisition_lines_all prl
INNER JOIN apps.po_requisition_headers_all prha ON prl.requisition_header_id = prha.requisition_header_id
INNER JOIN po.po_req_distributions_all prda ON prda.requisition_line_id = prl.requisition_line_id
LEFT JOIN po.po_distributions_all pda ON prda.distribution_id = pda.req_distribution_id
-- I note from the example provided that this is a right join
-- Without seeing the schema, it looks to me as though it should be left
-- As I say say, without seeing the schema, I probably shouldn't pass comment
RIGHT JOIN po.po_headers_all pha ON pha.po_header_id = pda.po_header_id;
对于 INNER JOIN
你可以只说 JOIN
虽然我认为明确地说 INNER
有助于提高可读性。我还注意到提供的示例有 WHERE 1=1
,这是多余的。
+是Outer Joins
的旧版本,与[=33不同=]+出现在等号之后或之前,但是现在建议使用Join
关键字而不是+
,关于+ 来了就签:
=之后:
select * from t1, t2
where t1.id=t2.id(+)
这意味着左外连接:
select * from t1
left outer join t2 on t1.id=t2.id
之前=:
select * from t1, t2
where t1.id(+)=t2.id
这意味着右外连接:
select * from t1
Right outer join t2 on t1.id=t2.id
没有+:
select * from t1, t2
where t1.id=t2.id
这意味着内连接:
select * from t1
join t2 on t1.id=t2.id