count duplicate values

How to find out the duplicate records of field values in the same table(2013-03-25 11:28:51)reproduced For example, there is now a table (table name: peosons) If you want to name, social Security number, address the three fields exactly the same

The SQL statement I used: Delete from fp_sgfpxxWhere fphm in (select fphm from fp_sgfpxx group by fphm having count (fphm)> 1)And rowid not in (select min (rowid) from fp_sgfpxx group by fphm having count (fphm)> 1) Delete duplicate invoice

Find duplicate data T-SQL in the database ========== first article ============ there are duplicate records under a field in a table, there are many ways, however, there is a method that is relatively efficient. The following statement: Select

Delete duplicate values in a single-chain table. duplicate values in a single-chain table.Question: Delete the elements that repeat values in a single-chain table of the lead node (that is, leave each value with only one element)Solution: Use a

MySQL prevent duplicate Insert Record method summaryThere are many ways to prevent MySQL from repeatedly inserting records, usually Ignore,replace,on DUPLICATE KEY UPDATE, which we can also judge in PHP.Scenario One: Using the Ignore keywordIf the

Although the SQL statements for querying and deleting duplicate records are messy, the content is still good. Although the SQL statements for querying and deleting duplicate records are messy, the content is still good. For example: Id name value 1

Original article: http://support.microsoft.com/kb/139444/SummaryThe Microsoft SQL Server table should not contain duplicate rows and non-unique primary keys. For the sake of conciseness, we sometimes refer to the primary key as "key" or "Pk" in this

How does mysql Delete duplicate record statements ?? For example, idnamevalue1app2app3biii4bpp5bpp6cpp7cpp8ciiiid is the primary key required to obtain this result idnamevalue1app3biii4bpp6cpp8ciii method 1 deleteYourTable How does mysql Delete

The Microsoft SQL Server table should not contain duplicate rows and non-unique primary keys. For the sake of conciseness, we sometimes refer to the primary key as "key" or "PK" in this article, but this always indicates "primary key ". Repeated PK

Scenario One: Using the Ignore keyword If the uniqueness of the record is distinguished by the primary key primary or unique index unique, it is possible to avoid duplicate insertion records: The code is as follows: The code is as