How to filter out duplicate data in sql

SQL method to filter out duplicate data: Use the "select * from table name where condition" statement to filter out duplicate data; you can use one or more tables, use commas (,) to separate the tables, and use WHERE statement to set query conditions.

The operating environment of this tutorial: windows7 system, mysql8 version, Dell G3 computer.

Open the database on your computer, and create a new user table with duplicate data as an example.

Query the duplicate data of the user table in the database.

select * from user where name in (select name from user group by name having count(name) > 1)

Delete duplicate name data

delete from user where   name in (select name from user group by name  having count(name) > 1)

Remove duplicate data, here the duplicate data of Zhang San is removed

select distinct name from user

Remove duplicate data of the same class

select distinct class from user

Remove duplicate data of two fields

select distinct name,class from user

Related free learning recommendations: mysql video tutorial

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