delete duplicate records in sql

Delete duplicate records in a table without a primary key CREATE PROCEDURE Delrepeat AsBeginSELECT distinct * into testtemp from testDelete from testINSERT INTO Test SELECT * from Testtempdrop table TesttempEnd Distinct: For removing duplicates in a query The Begin~end range statement represents a block of statements that are executed as a whole in a stored p

Label:;CREATE TABLEtabtest (' id 'INT( One) not NULLauto_increment, ' Factora 'VARCHAR(255) not NULL DEFAULT ' ', ' Factorb 'VARCHAR(255) not NULL DEFAULT ' ', ' Factorc 'DECIMAL(Ten,2) not NULL DEFAULT 0, ' remark 'VARCHAR(255) not NULL DEFAULT ' ' , PRIMARY KEY(' id ')) ENGINE=INNODB auto_increment=0 DEFAULTCHARSET=UTF8 COMMENT="'; INSERT intotabtest (Factora, Factorb, FACTORC, remark)SELECT 'A1','B1',0.5,'1..' UNION All SELECT 'A1','B1',0.5,'2..' UNION All SELECT 'A2','B2',0.5,'3..' UN

Tags: Use table not Eve to perform XXXX count check effectCheck for duplicate records --Check for duplicate code1 Select Count(Identity) Num,Identity fromEvent_logwhereCode='Code1' Group by Identity having Count(Identity)> 1 Order byNumdesc Delete duplicate

⑴ by creating a temporary table You can lead the data into a temporary table, and then delete the data from the original table, and then return the data back to the original table, the SQL statement is as follows: Sql>create table stu_tmp as select distinct* from Stu; sql>truncate table sut; Empty table record

use ofSELECT DISTINCT * FROM tablename You can get a result set without duplicate records. If the table needs to delete duplicate records (1 of duplicate records are retained), you c

Label:SQL statement for querying and deleting duplicate records1, look for redundant records in the table, duplicate records are based on a single field (Peopleid) to determineSELECT * from Peoplewhere Peopleid in (select Peopleid from People GROUP by Peopleid have count (Peopleid) > 1)2,

The principle of MySQL deleting duplicate records is:After placing the column to be compared to group by, remove the minimum value of the primary key, and then delete the row that is not in the primary key of the temporary tableThe command line format is as followsDelete from the users where ID not in (the Select ID from the (select min (id) from the Users group

This article provides a large number of SQL statement statements for deleting duplicate records. If you are worrying about how to delete duplicate data in the database, we provide you with a variety of SQL query statements for del

We can delete duplicate records in the following ways: Example: Table name: dbo. Variety Description $, field includes: ID_PK, breed name, trait standard number, code, first create a table that is the same as the original table structure: Copy Code code as follows: Select * into Tmpa from dbo. Breed Description $ where 1=2--created in datashe

We often encounter the need to delete repeated records in a data table. Below I will summarize several methods that can delete Repeated Records and help to improve efficiency. For more information, see. We often encounter the need to delete repeated

There are many ways to delete duplicate records. Here I summarize a variety of SQL statements for deleting restart records, such as deleting duplicate id data and searching for duplicate