Select where count of one field is greater than one

sql mysql

stevebot · Sep 14, 2010 · Viewed 290.1k times · Source

I want to do something like this:

SELECT * 
  FROM db.table 
 WHERE COUNT(someField) > 1

How can I achieve this in MySql?

Answer

Use the HAVING, not WHERE clause, for aggregate result comparison.

Taking the query at face value:

SELECT * 
  FROM db.table 
HAVING COUNT(someField) > 1

Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...

Is this in preparation for a unique constraint on someField? Looks like it should be...