mysql - 根据列和不同列的值选择行

Question

我想根据商店的数量选择具有不同商店位置的行，示例如下所示：

id   | item_name   | number_of_store| store_location|
+----+---------+-------------------+-------------+
|  3 | margarine | 2              | QLD         |
|  4 | margarine | 2              | NSW         |
|  5 | wine      | 3              | QLD         |
|  6 | wine      | 3              | NSW         |
|  7 | wine      | 3              | NSW         |
|  8 | laptop    | 1              | QLD         |
+----+---------+-------------------+-------------+

所需的结果如下所示：

id   | item_name   | number_of_store| store_location|
+----+---------+-------------------+-------------+
|  3 | margarine | 2              | QLD         |
|  4 | margarine | 2              | NSW         |
|  5 | wine      | 3              | QLD         |
|  6 | wine      | 3              | NSW         |
|  8 | laptop    | 1              | QLD         |
+----+---------+-------------------+-------------+

我不在乎返回哪个 id 列值。所需的 SQL 是什么？

标签： mysqlsql

Answer 1

你可以使用GROUP BY：

SELECT id, item_name ,number_of_store, store_location
FROM tab
GROUP BY  item_name ,number_of_store, store_location;
-- will work if ONLY_FULL_GROUP_BY is disabled

否则，您需要ANY_VALUE或聚合函数，例如MIN：

SELECT ANY_VALUE(id) AS id, item_name ,number_of_store, store_location
FROM tab
GROUP BY  item_name ,number_of_store, store_location;

DB-Fiddle.com 演示