HAVING句
説明
HAVING 句は、指定された条件に基づいて GROUP BY によって生成された結果をフィルタリングするために使用されます。これは、GROUP BY 句と組み合わせて使用されることがよくあります。
構文
HAVING boolean_expression
パラメータ
-
boolean_expression
結果の型が
booleanに評価される任意の式を指定します。2つ以上の式は、論理演算子（AND、OR）を使用して組み合わせることができます。注意
HAVING句で指定された式は、以下にのみ参照できます。- 定数
- GROUP BY に現れる式
- 集計関数
例
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|
+---+