Having vs Where

HAVING is used to check conditions after the aggregation takes place.

WHERE is used before the aggregation takes place.

This code:

select City, CNT=Count(1)
From Address
Where State = ‘MA’
Group By City

Gives you a count of all the cities in MA.

This code:

select City, CNT=Count(1)
From Address
Where State = ‘MA’
Group By City
Having Count(1)>5

Gives you the count of all the cities in MA that occur 6 or more times.