delete duplicate records in sql

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

For example, now there is a person table (table name: peosons)If you want to have the name, ID number, address of these three fields exactly the same records query Copy Code code as follows: Select p1.* From persons p1,persons P2 where p1.idand P1.cardid = P2.cardid and P1.pname = p2.pname and p1.address = p2.address can achieve this effect. Several SQL statements that

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 th

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 examp

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 primary key Ask for such a result 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 a From Table a LEFT join ( Select (ID) from table GROUP by Name,value ) B on A.id=b.id where b.id is null

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 n

SQL statement for querying and deleting duplicate records 1, 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

Write a SQL query to delete all duplicate e-mail entries in a table named Person , keeping unique emails based on its smallest Id. +----+------------------+| Id | Email |+----+------------------+| 1 | [Email protected] | | 2 | [email protected] | | 3 | [Email protected] |+----+------------------+id is the primary key, column for this ta

The ORACLE tutorial is: quickly delete duplicate records in oracle. When I was doing a project, a colleague accidentally duplicate all the data in a table while importing data. That is to say, all the records in this table have a record. This table has tens of millions of da

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

The Oracle tutorial you are looking at is how to determine duplicate records of Oracle database tables. As an Oracle Database developer or DBA, you often experience the problem of trying to create a unique index on a column or column in a library table, prompting ORA-01452: You cannot create a unique index and find duplicate