1757. 可回收且低脂的产品

Problem#

表：Products

1
+-------------+---------+
2
| Column Name | Type    |
3
+-------------+---------+
4
| product_id  | int     |
5
| low_fats    | varchar |
6
| recyclable  | varchar |
7
+-------------+---------+

product_id 是该表的主键。low_fats 和 recyclable 的取值为 'Y' 或 'N'。

找出既是低脂又是可回收的产品 ID。

https://leetcode.cn/problems/recyclable-and-low-fat-products/description/

示例：

输入：

1
| product_id | low_fats | recyclable |
2
|------------|----------|------------|
3
| 0          | Y        | N          |
4
| 1          | Y        | Y          |
5
| 2          | N        | Y          |
6
| 3          | Y        | Y          |
7
| 4          | N        | N          |

输出：

1
| product_id |
2
|------------|
3
| 1          |
4
| 3          |

思路#

简单的 WHERE 条件筛选。

1
```sql
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SELECT product_id
3
FROM Products
4
WHERE low_fats = 'Y' AND recyclable = 'Y';

1
```sql
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-- 测试数据
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CREATE TABLE Products (
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    product_id INT PRIMARY KEY,
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    low_fats VARCHAR(1),
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    recyclable VARCHAR(1)
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);
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INSERT INTO Products VALUES
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(0, 'Y', 'N'),
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(1, 'Y', 'Y'),
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(2, 'N', 'Y'),
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(3, 'Y', 'Y'),
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(4, 'N', 'N');
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-- 预期结果: 1, 3
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SELECT product_id FROM Products WHERE low_fats = 'Y' AND recyclable = 'Y';