Discover duplicate annihilator, include the articles, news, trends, analysis and practical advice about duplicate annihilator on alibabacloud.com
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 repeated record statements query and delete SQL statements for Repeated Records? ? For example: id name value 1 a pp 2 a pp 3 B iii 4 B pp 5 B pp 6 c pp 7 c pp 8 c iii id is the primary key requirement to get t
Tags: style io ar color using SP for strong onINSERT into on DUPLICATE key UPDATE with REPLACEinto, two commands can handle duplicate key-value problems, what difference does it make in practice?The precondition is that the table must have a unique index or primary key.1, replace found duplicate first delete and then insert, if the record has more than one field,
How does MySQL process duplicate data? Some MySQL Data Tables may have duplicate records. In some cases, we allow the existence of duplicate data, but sometimes we also need to delete these duplicate data.This section describes how to prevent duplicate data in a data table a
For example:Id name value1 a pp2 a pp3 B iii4 B pp5 B pp6 c pp7 c pp8 c iiiId is the primary keyThis result is required.Id name value1 a pp3 B iii4 B pp6 c pp8 c iiiMethod 1Delete YourTableWhere [id] not in (Select max ([id]) from YourTableGroup by (name + value ))Method 2DeleteFrom table a left join (Select (id) from Table group by name, value) B on a. id = B. idWhere B. id is nullSQL statement for querying and deleting duplicate recordsSQL statement
Original post address: http://www.cnblogs.com/phpliu/archive/2010/06/21/1761726.html For example:ID name value1 A PP2 A PP3 B III4 B PP5 B PP6 c pp7 c pp8 C IIIID is the primary keyThis result is required.ID name value1 A PP3 B III4 B PP6 c pp8 C III Method 1Delete yourtableWhere [ID] Not in (Select max ([ID]) from yourtableGroup by (name + value )) Method 2DeleteFrom table a left join (Select (ID) from Table group by name, Value) B on A. ID = B. IDWhere B. ID is null SQL statement for queryin
For example: ID name value 1 A PP 2 A PP 3 B III 4 B PP 5 B PP 6 c pp 7 c pp 8 C III ID is the primary key This result is required. ID name value 1 A PP 3 B III 4 B PP 6 c pp 8 C III Method 1 Delete yourtable Where [ID] Not in ( Select max ([ID]) from yourtable Group by (name + value )) Method 2 Delete From table a left join ( Select (ID) from Table group by name, Value ) B on A. ID = B. ID Where B. ID is null SQL statement for querying and deleting duplicat
For example: Id name value 1 a pp 2 a pp 3 B iii 4 B pp 5 B pp 6 c pp 7 c pp 8 c iii Id is the primary key This result is required. Id name value 1 a pp 3 B iii 4 B pp 6 c pp 8 c iii Method 1 Delete YourTable Where [id] not in ( Select max ([id]) from YourTable Group by (name + value )) Method 2 Delete From table a left join ( Select (id) from table group by name, value ) B on a. id = B. id Where B. id is null SQL statement for querying and deleting duplicat
Sometimes a table or result set contains duplicate records. Sometimes it is allowed, but sometimes it needs to stop repeating records. Sometimes it needs to recognize that duplicate records are removed from the table. This chapter describes how to prevent duplicate records from occurring in one table from deleting duplicates that already exist. Prevent occurrenc
Related Articles: MySQL "on duplicate key update" Syntax Insert into .. on duplicate key to update multiple rows Http://dev.mysql.com/doc/refman/5.1/zh/sql-syntax.html#insert MySQL "on duplicate key update" Syntax If the on duplicate key update is specified at the end of the insert statement and the
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 follows Copy Code INSERT IGNORE into ' table_name ' (' email ', ' phone ', ' user_id ') VALUES (' test9@163.com ', ' 99999 ', ' 9999 '); This will be ignored when
ObjectiveThis article mainly introduces to you about MySQL query, delete duplicate record of method, share out for everyone reference study, below to see detailed introduction:Find records for all repeating headings:? 1 selecttitle,count(*) as count from user_table group by title havingcount>1; ? 1 SELECT* FROM t_info a WHERE ((SELECT COUNT(*) FROM t_info WHERE Title = a.Title) > 1) ORDER BYTitle DE
Tags: oid delete query drop person where copy Deb action methodThis article lists 3 ways to delete duplicate records, namely ROWID, group by and distinct, which can be consulted by small partners.For example, there is now a person table (table name: peosons)If you want to name, ID, address, the three fields exactly the same record queryThe code is as follows: Select p1.*From persons p1,persons P2where p1.idand P1.cardid = P2.cardid and P1.pname = p2.p
SQL statement for data duplication between Oracle and MySQL It can be said that this data is repeated, no matter in development, data maintenance and experience interviews, you should encounter common problems! Here, I also paid special attention to some articles on the Internet and collected them for your reference and study. It also facilitates your future review! Repeated data processing in Oracle How to query duplicate data Select Field 1, Field
DupeGuru-find and remove duplicate files directly from the hard diskIntroduction For us, disk installation is a tough issue. No matter how careful we are, we may always copy the same file to multiple different places or download the same file without knowing it. Therefore, sooner or later you will see the error message "the disk is full". If we really need some disk space to store important data at this time, the above situation is undoubtedly the wor
Label: Suppose you have a table of people (table name: person), if you want to name, ID number, address the three fields exactly the same records to find out, using 1: SELECT p1.* 2: From persons p1,persons p2 3: WHERE p1.id 4: And p1.cardid = p2.cardid 5: And p1.pname = p2.pname 6: And p1.address = p2.address This functionality can be implemented. SQL statement to delete
Label:SELECT *From T_info AWHERE (SELECT COUNT (*)From T_infoWHERE Title = a.title) > 1)ORDER by Title DESC One. Find Duplicate Records 1. Find all duplicate records SELECT * FROM table Where repeating field in (Select repeating field from table Group by repeating field having Count (*) >1) 2. Filter duplicate records (show only one bar) SELECT * from Hzt Where I
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 record query outSelect p1.* from Persons p1,persons P2where p1.idp2.id and P1.cardid = P2.cardid and P1.pname = p2.pname and p1.address = p2.address can achieve this effect.Several SQL statements that delete
Tags: a 2.4 Strong database table function contains attention to direct spanMySQL "on DUPLICATE KEY UPDATE" syntaxIf an on DUPLICATE KEY UPDATE is specified at the end of the INSERT statement, and the row is inserted to cause duplicate values in a unique index or primary KEY, UPDATE is performed on the row where the duplicate
Tags: level resdeclare ignore size sqlorapre storage structure Query and delete duplicate records of SQL statements 1, find redundant duplicate records in the table, duplicate records are based on a single field (ID) to judge SELECT * from table where Id in (select ID from table group Byid h aving count (ID) > 1) 2, delete redundant
SELECT *From T_info AWHERE (SELECT COUNT (*)From T_infoWHERE Title = a.title) > 1)ORDER by Title DESCOne. Find Duplicate Records1. Find all duplicate recordsSELECT * FROM table Where repeating field in (Select repeating field from table Group by repeating field having Count (*) >1)2. Filter duplicate records (show only one bar)SELECT * from Hzt Where ID in (the S
Start building with 50+ products and up to 12 months usage for Elastic Compute Service
1 on 1 presale consultation
24/7 Technical Support 6 Free Tickets per Quarter Faster Response
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.
A comprehensive suite of global cloud computing services to power your business
Payment Methods We Support
