Login | Register   
RSS Feed
Download our iPhone app
Browse DevX
Sign up for e-mail newsletters from DevX

By submitting your information, you agree that devx.com may send you DevX offers via email, phone and text message, as well as email offers about other products and services that DevX believes may be of interest to you. DevX will process your information in accordance with the Quinstreet Privacy Policy.

Tip of the Day
Language: Enterprise
Expertise: Beginner
Apr 11, 2000



Building the Right Environment to Support AI, Machine Learning and Deep Learning

Delete Duplicate Rows in a SQL Table

There are times when duplicate records somehow creep into a table despite your best efforts. This happens more in cases where data is loaded into table from other sources because during data loads, the integrity constraints are disabled.

The following SQL statement helps in deleting the duplicate rows in a table:

 delete table_a 
where rowid not in 
     (select min(rowid) from table_a 
       group by column1, column2);
In the above Data Manipulation Language statement, the sub-query should be grouped by all the columns that are part of the primary/unique key. In the above case it is column1 and column2.
Jayanta Sengupta
Comment and Contribute






(Maximum characters: 1200). You have 1200 characters left.



Thanks for your registration, follow us on our social networks to keep up-to-date