HAVING (clause)HAVING clause

La HAVING clause est utilisée pour filtrer les résultats produits par en GROUP BY fonction de la condition spécifiée.The HAVING clause is used to filter the results produced by GROUP BY based on the specified condition. Il est souvent utilisé conjointement à une clause Group by .It is often used in conjunction with a GROUP BY clause.

SyntaxeSyntax

HAVING boolean_expression

ParamètresParameters

  • boolean_expressionboolean_expression

    Spécifie toute expression qui prend la valeur d’un type de résultat boolean .Specifies any expression that evaluates to a result type boolean. Au moins deux expressions peuvent être combinées à l’aide des opérateurs logiques ( AND , OR ).Two or more expressions may be combined together using the logical operators ( AND, OR ).

    RemarqueNote

    Les expressions spécifiées dans la HAVING clause peuvent uniquement faire référence à :The expressions specified in the HAVING clause can only refer to:

    1. ConstantesConstants
    2. Expressions qui s’affichent dans GROUP BYExpressions that appear in GROUP BY
    3. Fonctions d'agrégationAggregate functions

ExemplesExamples

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|
+---+