HAVING clause - Amazon Redshift

HAVING clause

The HAVING clause applies a condition to the intermediate grouped result set that a query returns.

Syntax

[ HAVING condition ]

For example, you can restrict the results of a SUM function:

having sum(pricepaid) >10000

The HAVING condition is applied after all WHERE clause conditions are applied and GROUP BY operations are completed.

The condition itself takes the same form as any WHERE clause condition.

Usage notes

  • Any column that is referenced in a HAVING clause condition must be either a grouping column or a column that refers to the result of an aggregate function.

  • In a HAVING clause, you can't specify:

    • An ordinal number that refers to a select list item. Only the GROUP BY and ORDER BY clauses accept ordinal numbers.

Examples

The following query calculates total ticket sales for all events by name, then eliminates events where the total sales were less than $800,000. The HAVING condition is applied to the results of the aggregate function in the select list: sum(pricepaid).

select eventname, sum(pricepaid) from sales join event on sales.eventid = event.eventid group by 1 having sum(pricepaid) > 800000 order by 2 desc, 1; eventname | sum ------------------+----------- Mamma Mia! | 1135454.00 Spring Awakening | 972855.00 The Country Girl | 910563.00 Macbeth | 862580.00 Jersey Boys | 811877.00 Legally Blonde | 804583.00 (6 rows)

The following query calculates a similar result set. In this case, however, the HAVING condition is applied to an aggregate that isn't specified in the select list: sum(qtysold). Events that did not sell more than 2,000 tickets are eliminated from the final result.

select eventname, sum(pricepaid) from sales join event on sales.eventid = event.eventid group by 1 having sum(qtysold) >2000 order by 2 desc, 1; eventname | sum ------------------+----------- Mamma Mia! | 1135454.00 Spring Awakening | 972855.00 The Country Girl | 910563.00 Macbeth | 862580.00 Jersey Boys | 811877.00 Legally Blonde | 804583.00 Chicago | 790993.00 Spamalot | 714307.00 (8 rows)