How to remove duplicates in MySQL database
In this issue, the editor will bring you about how to remove weight in the MySQL database. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.
Using distinct
De-duplicate the fields that need to be processed
Select distinct field name from table name
Using group by
Select * from table name group by field name
Using having
Select * from table name group by field name having field name = required
The difference between where and having
After 1.having is used for group by
2.where is used to filter queries in tables, and having is used to query in where and group results
3.having can use aggregate functions, while where cannot
The execution order of 4.having comes after where
The above is how to achieve duplication in the MySQL database shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.