Select where count of one field is greater than one

Question

I want to do something like this:

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

How can I achieve this in MySql?

Answer 1

One way

SELECT t1.* 
FROM db.table t1
WHERE exists 
      (SELECT *
      FROM db.table t2 
      where t1.pk != t2.pk 
      and t1.someField = t2.someField)