IN (SELECT 字段1,字段2,字段3 FROM (SELECT 字段1,字段2,字段3 FROM 表名 GROUP BY 字段1,字段2,字段3 HAVING COUNT(*)>1) s1) AND id NOT IN (SELECT id FROM (SELECT id FROM 表名 GROUP BY 字段1,字段2,字段3 HAVING COUNT(*)>1) s2);
sql 查出一張表中重復的所有記錄數據
1.表中有id和name 兩個字段，查詢出name重復的所有數據
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1
|
select
*
from
xi a
where
(a.username)
in
(
select
username
from
xi
group
by
username
having
count
(*) > 1)
|
2、查詢出所有數據進行分組之后，和重復數據的重復次數的查詢數據，先列下：
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1
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select
count
(username)
as
'重復次數'
,username
from
xi
group
by
username
having
count
(*)>1
order
by
username
desc
|
3、一下為 查看別人的 結果，現列下：查詢及刪除重復記錄的方法大全
1、查找表中多余的重復記錄，重復記錄是根據單個字段（peopleId）來判斷
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1
2
|
select
*
from
people
where
peopleId
in
(
select
peopleId
from
people
group
by
peopleId
having
count
(peopleId) > 1)
|
2、刪除表中多余的重復記錄，重復記錄是根據單個字段（peopleId）來判斷，只留有rowid最小的記錄
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1
2
3
|
delete
from
people
where
peopleId
in
(
select
peopleId
from
people
group
by
peopleId
having
count
(peopleId) > 1)
and
rowid
not
in
(
select
min
(rowid)
from
people
group
by
peopleId
having
count
(peopleId )>1)
|
3、查找表中多余的重復記錄（多個字段）
|
1
2
|
select
*
from
vitae a
where
(a.peopleId,a.seq)
in
(
select
peopleId,seq
from
vitae
group
by
peopleId,seq
having
count
(*) > 1)
|
4、刪除表中多余的重復記錄（多個字段），只留有rowid最小的記錄
|
1
2
3
|
delete
from
vitae a
where
(a.peopleId,a.seq)
in
(
select
peopleId,seq
from
vitae
group
by
peopleId,seq
having
count
(*) > 1)
and
rowid
not
in
(
select
min
(rowid)
from
vitae
group
by
peopleId,seq
having
count
(*)>1)
|
5、查找表中多余的重復記錄（多個字段），不包含rowid最小的記錄
|
1
2
3
|
select
*
from
vitae a
where
(a.peopleId,a.seq)
in
(
select
peopleId,seq
from
vitae
group
by
peopleId,seq
having
count
(*) > 1)
and
rowid
not
in
(
select
min
(rowid)
from
vitae
group
by
peopleId,seq
having
count
(*)>1)
|
(二)
比方說
在A表中存在一個字段“name”，
而且不同記錄之間的“name”值有可能會相同，
現在就是需要查詢出在該表中的各記錄之間，“name”值存在重復的項；
|
1
|
Select
Name
,
Count
(*)
From
A
Group
By
Name
Having
Count
(*) > 1
|
如果還查性別也相同大則如下:
|
1
|
Select
Name
,sex,
Count
(*)
From
A
Group
By
Name
,sex
Having
Count
(*) > 1
|
(三)
方法一
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1
2
3
4
5
6
7
8
9
10
11
|
declare
@
max
integer
,@id
integer
declare
cur_rows
cursor
local
for
select
主字段,
count
(*)
from
表名
group
by
主字段
having
count
(*) >;
open
cur_rows
fetch
cur_rows
into
@id,@maxwhile @@fetch_status=0
begin
select
@
max
= @
max
-1
set
rowcount @
max
delete
from
表名
where
主字段 = @id
fetch
cur_rows
into
@id,@maxend
close
cur_rows
set
rowcount 0
|
方法二＂重復記錄＂有兩個意義上的重復記錄，一是完全重復的記錄，也即所有字段均重復的記錄，二是部分關鍵字段重復的記錄，比如Name字段重復，而其他字段不一定重復或都重復可以忽略。
1、對於第一種重復，比較容易解決，使用
|
1
|
select
distinct
*
from
tableName
|
就可以得到無重復記錄的結果集。
如果該表需要刪除重復的記錄（重復記錄保留1條），
可以按以下方法刪除
|
1
2
3
4
|
select
distinct
*
into
#Tmp
from
tableName
drop
table
tableName
select
*
into
tableName
from
#Tmp
drop
table
#Tmp
|
發生這種重復的原因是表設計不周產生的，增加唯一索引列即可解決。
2、這類重復問題通常要求保留重復記錄中的第一條記錄，操作方法如下 假設有重復的字段為Name,Address，要求得到這兩個字段唯一的結果集
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1
2
3
|
select
identity(
int
,1,1)
as
autoID, *
into
#Tmp
from
tableName
select
min
(autoID)
as
autoID
into
#Tmp2
from
#Tmp
group
by
Name
,autoID
select
*
from
#Tmp
where
autoID
in
(
select
autoID
from
#tmp2)
|
最后一個select即得到了Name，Address不重復的結果集（但多了一個autoID字段，實際寫時可以寫在select子句中省去此列）
(四)查詢重復
|
1
|
select
*
from
tablename
where
id
in
(
select
id
from
tablenamegroup
by
idhaving
count
(id) > 1)
|
對一個字段查找重復記錄
根據sample_code字段找到重復記錄
|
1
|
SELECT
*
FROM
tb_table
WHERE
sample_code
IN
(
SELECT
sample_code
FROM
tb_table
GROUP
BY
sample_code
HAVING
COUNT
(sample_code) > 1 );
|
對多個字段查找重復記錄（這里以2個為例）
根據name和code字段找到重復記錄
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4
|
SELECT
*
from
(
SELECT
*, CONCAT(
name
,code)
as
nameAndCode
from
tb_table) t
WHERE
t.nameAndCode
in
(
SELECT
nameAndCode
from
(
SELECT
CONCAT(
name
,code)
as
nameAndCode
from
tb_table) tt
GROUP
BY
nameAndCode
HAVING
count
(nameAndCode) > 1
)
|
總結
以上所述是小編給大家介紹的MySQL根據某一個或者多個字段查找重復數據的sql語句，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回復大家的。在此也非常感謝大家對腳本之家網站的支持！