How do I find out if there's any duplicate records in a table?

or if there's any 2 or more records with identical value of one of the columns?

 

select col1, col2
from table
group by col1, col2
having count(*) > 1

 

Thanks. Got it done by this:

SELECT name, COUNT(name) FROM authors GROUP BY name HAVING (COUNT(name))

It's really tricky to handle intricate SQL to do things you previously can't think about.

 

There is no need to use COUNT() twice

SELECT name, COUNT(*) cnt FROM authors GROUP BY name HAVING cnt>1

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