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作 者： 我本有心
QQ: 381584252
E-Mail: [email protected]
轉載請註明出處及作者！
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http://www.8848so.com，人物搜索，8848So
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注：此處“重複”非完全重複,意爲某字段數據重複
HZT表結構
ID int
Title nvarchar(50)
AddDate datetime
數據
| ID | Title | AddDate |
| 1 | 我本有心1 | 2008-01-17 10:27:24.827 |
| 2 | 我本有心1 | 2008-03-17 10:27:21.780 |
| 3 | 我本有心2 | 2008-05-17 10:27:30.420 |
| 4 | 我本有心2 | 2008-09-17 10:27:30.420 |
| 5 | 我本有心3 | 2008-01-20 10:27:30.420 |
| 6 | 我本有心3 | 2008-01-15 10:27:30.420 |
| 7 | QQ:381584252 | 2008-01-19 10:27:30.420 |
| 8 | QQ:381584252 | 2008-01-18 10:27:30.420 |
| 9 | Email:[email protected] | 2001-01-17 10:27:30.420 |
| 10 | Email:[email protected] | 2009-01-17 10:27:30.420 |
| 11 | HZT | 2005-01-17 10:27:30.420 |
| 12 | 1314521 | 2006-01-17 10:27:30.420 |
| 13 | LoveCY | 2007-01-17 10:27:30.420 |
| 14 | 19861108 | 2008-03-17 10:27:30.420 |
| 15 | CY | 2008-02-17 10:27:30.420 |
一。查找重複記錄
1。查找全部重複記錄
Select * From 表 Where 重複字段 In (Select 重複字段 From 表 Group By 重複字段 Having Count(*)>1)
2。過濾重複記錄(只顯示一條)
Select * From HZT Where ID In (Select Max(ID) From HZT Group By Title)
注：此處顯示ID最大一條記錄
二。刪除重複記錄
1。刪除全部重複記錄（慎用）Delete 表 Where 重複字段 In (Select 重複字段 From 表 Group By 重複字段 Having Count(*)>1)
2。保留一條（這個應該是大多數人所需要的 ^_^）
Delete HZT Where ID Not In (Select Max(ID) From HZT Group By Title)
注：此處保留ID最大一條記錄
