选择 - 查找重复项 [英] Select - find duplicates
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问题描述
嗨
我有一些DB2表,其中主键通常是唯一的,但可以重复
。
我想找到仅重复。
例如,假设主键具有以下值:
21
28
30
30
34
40
52
52
我只想知道30和52左右。
我能用聪明的SQL语句做这个吗?
TIA
Hi
I have some DB2 tables where the primary key is usually unique, but can
be duplicate.
I want to find the duplicates only.
For example, suppose the primary key has these values:
21
28
30
30
34
40
52
52
I want to know about 30 and 52 only.
Can I do this with a clever SQL statement?
TIA
推荐答案
Nananana写道:
Nananana wrote:
嗨
我有一些DB2表,其中主键通常是唯一的,但可以重复
。
我只想找到重复项。
例如,假设主键具有以下值:
21
28
30
30
34
40
52
52
我想知道大约30和52只有。
我能用聪明的SQL语句做这个吗?
TIA
Hi
I have some DB2 tables where the primary key is usually unique, but can
be duplicate.
I want to find the duplicates only.
For example, suppose the primary key has these values:
21
28
30
30
34
40
52
52
I want to know about 30 and 52 only.
Can I do this with a clever SQL statement?
TIA
使用GROUP BY和HAVING COUNT(*)1
Use GROUP BY and HAVING COUNT(*) 1
在2007-01-16 10:37,Nananana写道:
On 2007-01-16 10:37, Nananana wrote:
我有一些DB2表,其中主键通常是唯一的,但可以重复
。
I have some DB2 tables where the primary key is usually unique, but can
be duplicate.
我不这么认为。主键是唯一的。根据定义。
Benjamin
I don''t think so. Primary keys are unique. By definition.
Benjamin
太棒了 - 谢谢。
我甚至让它工作
:-)
Tonkuma写道:
Great - thanks.
I even got it to work
:-)
Tonkuma wrote:
Nananana写道:
Nananana wrote:
嗨
我有一些DB2表,其中主键通常是唯一的,但可以重复
。 br />
我只想找到重复项。
例如,假设主键具有以下值:
21 >
28
30
30
34
40
52
52
我只想知道30和52左右。
我能用巧妙的SQL语句做到这一点吗?
TIA
Hi
I have some DB2 tables where the primary key is usually unique, but can
be duplicate.
I want to find the duplicates only.
For example, suppose the primary key has these values:
21
28
30
30
34
40
52
52
I want to know about 30 and 52 only.
Can I do this with a clever SQL statement?
TIA
使用GROUP BY和HAVING COUNT(*)1
Use GROUP BY and HAVING COUNT(*) 1
>
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