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I want to do something like this:

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

How can I achieve this in MySql?

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1 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...


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
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