ORACLE中WHERE语句中的IF / ELSE [英] IF/ELSE in WHERE statement in ORACLE

问题描述

您好，



我正在尝试将IF / ELSE或CASE / WHEN应用于我的选择语句，但我没有成功。有人可以帮我怎么写这个吗？



我的查询是：

Hello,

I am trying to apply IF/ELSE or CASE/WHEN to my select statement but I am not successful. Can someone help me how to write this?

My query is:

SELECT P.*
FROM PTABLE P, MTABLE M, NTABLE N
WHERE 
    CASE 
       WHEN P.MATERIAL IS NOT NULL THEN M.MATERIAL = N.MATERIAL
       WHEN P.MATERIAL IS NULL THEN M.MATERIAL = P.MATERIAL
    END

我尝试了但是我在该查询中收到错误。作为一种替代方案，我尝试应用其他但没有好处。

所以我的陈述应该类似于

I tried that but I get error on that query. As an alternative I tried appliying if else but no good.
So my statement should be something like

IF P.MATERIAL IS NOT NULL THEN
M.MATERIAL = N.MATERIAL 
ELSE 
M.MATERIAL = P.MATERIAL

提前致谢

Thanks in advance

推荐答案

试试这个，

Try This,

SELECT P.*
FROM PTABLE P
LEFT JOIN MTABLE M ON P.MATERIALID = M.MATERIALID
LEFT JOIN NTABLE R ON P.MATERIALID = N.MATERIALID
WHERE
    M.MATERIAL = CASE WHEN P.MATERIAL IS NOT NULL THEN N.MATERIAL ELSE P.MATERIAL END

快乐编码！

：）

Happy Coding!
:)

嗨...



使用带有解码功能的查询

Hi...

Use this Query with Decode function

SELECT P.*
FROM PTABLE P,MTABLE M,NTABLE R
WHERE P.MATERIALID = M.MATERIALID
  AND P.MATERIALID = N.MATERIALID
  AND P.MATERIAL = DEOCDE(P.MATERIAL,NULL,P.MATERIAL,N.MATERIAL)

如果您有任何澄清，请不要犹豫联系我。谢谢。

If you have any clarification,please don''t hesitate to contact me. Thank you.

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