Having Clause

When you are doing a summary query, you can also specify a Having clause. This is like a Where clause, except that it involves a summary value, rather than a column value.

In our example of customer revenue, the following query shows you customer revenue when it is more than $1000:

Select customer_code, month, sum(revenue) from orders group by customer_code, month having sum(revenue) > 1000

In a summary query, the Where tab and Where Clause windows include options for dealing with Having Clauses

Having versus Where

The easiest way to understand the difference between a Where clause and a Having clause is as follows.

• A Where clause specifies the rows in your table(s) to be included in the summation
• The Having clause operates after the summation has been done. It specifies which of the summary rows are returned in your resultset.