加入3个表并从第3个表中获取最新记录（如果不存在）显示最新的第2个表 [英] Join 3 tables and fetch for latest record from 3rd table if not exists display latest from 2nd table

问题描述

请在这里找到小提琴

我的要求是我需要根据第一个表ID和第二个表ID显示第3个表中的最新记录，如果不是我想显示最新的从第二张表记录。我已经给出了样本表和我写的查询，但是根据我的需要得不到实际结果所以有人可以帮助我

SQL小提琴



这就是我得到的东西，我写的是我的预期



http://i.stack.imgur.com/KCFkA.png [ ^ ]

Please find the fiddle here
My requirement is I need to display the latest record from 3rd table if exists based on first table ID and second table ID, if not I would like to display the latest record from second table. I have given the sample tables and the query I have written but i am not getting the actual result as per my need so some one can help me
SQL Fiddle

This is what I am getting and I have written what I expected

http://i.stack.imgur.com/KCFkA.png[^]

推荐答案

我无法从工作中访问图像URL。但我想我可能已经理解了你需要的东西。您可以在查询中添加更多列。

I can't access the image URL from work. But I guess I may have understood what you need. You can add more columns to the query.

SELECT	ISNULL(CDESC,BDESC) 
FROM	TBLA JOIN TBLB 
ON		TBLA.AID = TBLB.AID
		LEFT JOIN TBLC 
ON		(TBLB.BID = TBLC.BID AND TBLB.AID = TBLC.AID)
ORDER BY TBLC.CID DESC,TBLB.BID DESC

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