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sql-ref-syntax-qry-select-having.md

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HAVING Clause
HAVING Clause
Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

The HAVING clause is used to filter the results produced by GROUP BY based on the specified condition. It is often used in conjunction with a GROUP BY clause.

Syntax

{% highlight sql %} HAVING boolean_expression {% endhighlight %}

Parameters

boolean_expression
Specifies any expression that evaluates to a result type boolean. Two or more expressions may be combined together using the logical operators ( AND, OR ).

<b>Note</b><br>
The expressions specified in the <code>HAVING</code> clause can only refer to:
 <ol>
  <li>Constants</li>
  <li>Expressions that appear in GROUP BY</li>
  <li>Aggregate functions</li>
</ol>

Examples

{% highlight sql %} CREATE TABLE dealer (id INT, city STRING, car_model STRING, quantity INT); INSERT INTO dealer VALUES (100, 'Fremont', 'Honda Civic', 10), (100, 'Fremont', 'Honda Accord', 15), (100, 'Fremont', 'Honda CRV', 7), (200, 'Dublin', 'Honda Civic', 20), (200, 'Dublin', 'Honda Accord', 10), (200, 'Dublin', 'Honda CRV', 3), (300, 'San Jose', 'Honda Civic', 5), (300, 'San Jose', 'Honda Accord', 8);

-- HAVING clause referring to column in GROUP BY. SELECT city, sum(quantity) AS sum FROM dealer GROUP BY city HAVING city = 'Fremont';

+-------+---+ |city |sum| +-------+---+ |Fremont|32 | +-------+---+

-- HAVING clause referring to aggregate function. SELECT city, sum(quantity) AS sum FROM dealer GROUP BY city HAVING sum(quantity) > 15;

+-------+---+ | city|sum| +-------+---+ | Dublin| 33| |Fremont| 32| +-------+---+

-- HAVING clause referring to aggregate function by its alias. SELECT city, sum(quantity) AS sum FROM dealer GROUP BY city HAVING sum > 15;

+-------+---+ | city|sum| +-------+---+ | Dublin| 33| |Fremont| 32| +-------+---+

-- HAVING clause referring to a different aggregate function than what is present in -- SELECT list. SELECT city, sum(quantity) AS sum FROM dealer GROUP BY city HAVING max(quantity) > 15;

+------+---+ |city |sum| +------+---+ |Dublin|33 | +------+---+

-- HAVING clause referring to constant expression. SELECT city, sum(quantity) AS sum FROM dealer GROUP BY city HAVING 1 > 0 ORDER BY city;

+--------+---+ | city|sum| +--------+---+ | Dublin| 33| | Fremont| 32| |San Jose| 13| +--------+---+

-- HAVING clause without a GROUP BY clause. SELECT sum(quantity) AS sum FROM dealer HAVING sum(quantity) > 10; +---+ |sum| +---+ | 78| +---+

{% endhighlight %}

Related Clauses