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  • 5.删除数据

    DELETE FROM table_name [WHERE <condition>];
    

    table_name表示要执行删除操作的表;[WHERE ]为可选参数,用于指定删除条件,如果没有WHERE子句,DELETE语句将删除表中所有记录。
    例:删除person表中,id=11的记录:
    删除前:

    mysql> SELECT * FROM person;
    +----+---------+-----+-----------+
    | id | name    | age | info      |
    +----+---------+-----+-----------+
    |  1 | Green   |  21 | student   |
    |  2 | Suse    |  22 | student   |
    |  3 | Mary    |  24 | Musician  |
    |  4 | Willam  |  20 | student   |
    |  5 | Laura   |  25 | NULL      |
    |  6 | Evans   |  27 | secretary |
    |  7 | Dale    |  22 | student   |
    |  8 | Edison  |  28 | singer    |
    | 11 | LiMing  |  15 | student   |
    | 12 | Beckham |  31 | police    |
    +----+---------+-----+-----------+
    10 rows in set (0.00 sec)
    

    删除:

    mysql> DELETE FROM person WHERE id=11;
    Query OK, 1 row affected (0.19 sec)
    

    删除后:

    mysql> SELECT * FROM person;
    +----+---------+-----+-----------+
    | id | name    | age | info      |
    +----+---------+-----+-----------+
    |  1 | Green   |  21 | student   |
    |  2 | Suse    |  22 | student   |
    |  3 | Mary    |  24 | Musician  |
    |  4 | Willam  |  20 | student   |
    |  5 | Laura   |  25 | NULL      |
    |  6 | Evans   |  27 | secretary |
    |  7 | Dale    |  22 | student   |
    |  8 | Edison  |  28 | singer    |
    | 12 | Beckham |  31 | police    |
    +----+---------+-----+-----------+
    9 rows in set (0.00 sec)
    

    例:
    在person表中使用DELETE语句同时删除多条记录:

    mysql> SELECT * FROM person WHERE age BETWEEN 19 AND 22;
    +----+--------+-----+---------+
    | id | name   | age | info    |
    +----+--------+-----+---------+
    |  1 | Green  |  21 | student |
    |  2 | Suse   |  22 | student |
    |  4 | Willam |  20 | student |
    |  7 | Dale   |  22 | student |
    +----+--------+-----+---------+
    4 rows in set (0.00 sec)
    

    删除:

    mysql> DELETE FROM person WHERE age BETWEEN 19 AND 22;
    Query OK, 4 rows affected (0.07 sec)
    

    删除后:

    mysql> SELECT * FROM person WHERE age BETWEEN 19 AND 22;
    Empty set (0.00 sec)
    

    例:删除person表中所有记录:
    删除前:

    mysql> SELECT * FROM person;
    +----+---------+-----+-----------+
    | id | name    | age | info      |
    +----+---------+-----+-----------+
    |  3 | Mary    |  24 | Musician  |
    |  5 | Laura   |  25 | NULL      |
    |  6 | Evans   |  27 | secretary |
    |  8 | Edison  |  28 | singer    |
    | 12 | Beckham |  31 | police    |
    +----+---------+-----+-----------+
    5 rows in set (0.00 sec)
    

    删除:

    mysql> DELETE FROM person;
    Query OK, 5 rows affected (0.02 sec)
    

    删除后:

    mysql> SELECT * FROM person;
    Empty set (0.00 sec)
    
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  • 原文地址:https://www.cnblogs.com/xiaotufei/p/13338441.html
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