查找与SQL中的列相关的表的区别 [英] Find Distinct of a table with respect to a column in SQL

问题描述

大家好，

我有一个包含三列的Sql表。

 Id ItemId Item 
 1 1狗
 2 1 Dog1 
 3 2 Cat 
 4 2 Cat1 
 5 3 Lion 
 6 3 Lion1 

现在我必须找到这个表的不同之处。关于项目ID。请帮我写下存储过程。输出应该是这样的。

 Id ItemId项目
 2 1 Dog1 
 4 2 Cat1 
 6 3 Lion1 

解决方案

试试这个：

  SELECT  t1.ID，t1.ITEMID，t2.ITEM 
  FROM （
  SELECT  MAX（ID）ID，ITEMID 
  FROM  A 
  GROUP   BY  ITEMID 
） AS  t1  INNER   JOIN  A  AS  t2  ON  t1.ID = t2.ID 

SqlFiddle [ ^

Hi All,
I Have an Sql table with three columns.

Id    ItemId	Item
1	1	Dog
2	1	Dog1
3	2	Cat
4	2	Cat1
5	3	Lion
6	3	Lion1

Now I have to find distinct of this table. with respect to Item Id. Please help me with it to write stored Procedure. Output should be Like this.

Id    ItemId	Item
2	1	Dog1
4	2	Cat1
6	3	Lion1

解决方案

Try this:

SELECT t1.ID, t1.ITEMID, t2.ITEM
FROM (
  SELECT MAX(ID) ID, ITEMID
  FROM A
  GROUP BY ITEMID
) AS t1 INNER JOIN A AS t2 ON t1.ID = t2.ID

SqlFiddle[^]

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