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  • mysql逻辑运算符

    1. AND

      逻辑与,且运算;

      如:select prod_name,prod_price from products where prod_name='1 ton anvil' AND prod_price <= 10.00

    +-------------+------------+
    | prod_name | prod_price |
    +-------------+------------+
    | 1 ton anvil | 9.99 |
    +-------------+------------+
    1 row in set (0.00 sec)

    2. OR

      逻辑或,或运算;

      如:select prod_name,prod_price from products where prod_name='1 ton anvil' or prod_price <= 10.00;

    +----------------+------------+
    | prod_name      | prod_price |
    +----------------+------------+
    | .5 ton anvil   |       5.99 |
    | 1 ton anvil    |       9.99 |
    | Bird seed      |      10.00 |
    | Carrots        |       2.50 |
    | Fuses          |       3.42 |
    | Oil can        |       8.99 |
    | Sling          |       4.49 |
    | TNT (1 stick)  |       2.50 |
    | TNT (5 sticks) |      10.00 |
    +----------------+------------+
    9 rows in set (0.00 sec)

    3. NOT

      逻辑非。非运算;

       如,select prod_name,prod_price from products where NOT prod_name='1 ton anvil';

    +----------------+------------+
    | prod_name      | prod_price |
    +----------------+------------+
    | .5 ton anvil   |       5.99 |
    | 2 ton anvil    |      14.99 |
    | Detonator      |      13.00 |
    | Bird seed      |      10.00 |
    | Carrots        |       2.50 |
    | Fuses          |       3.42 |
    | JetPack 1000   |      35.00 |
    | JetPack 2000   |      55.00 |
    | Oil can        |       8.99 |
    | Safe           |      50.00 |
    | Sling          |       4.49 |
    | TNT (1 stick)  |       2.50 |
    | TNT (5 sticks) |      10.00 |
    +----------------+------------+
    13 rows in set (0.00 sec)

    4. IN

      指定条件范围内的数据

      如:select prod_name,prod_price from products where prod_name in ('1 ton anvil', '2 ton anvil');

    +-------------+------------+
    | prod_name   | prod_price |
    +-------------+------------+
    | 1 ton anvil |       9.99 |
    | 2 ton anvil |      14.99 |
    +-------------+------------+
    2 rows in set (0.00 sec)

     注意:存在混合逻辑运算时,应该使用括号进行限定;

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  • 原文地址:https://www.cnblogs.com/weiyouqing/p/14689859.html
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