mysql desc(DESCRIBE)命令实例讲解

5年以前  |  阅读数:676 次  |  编程语言:PHP 

mysql desc命令用于查看表结构,是DESCRIBE命令的简写形式。

mysql desc命令语法:

desc tablename

该命令会显示表哪些信息呢?具体包括:

  1. 字段名称(Field)
  2. 字段类型(Type)
  3. 字段是否为null
  4. 字段是否为主键(key)
  5. 字段的默认值(default)
  6. Extra

实例:


    mysql> CREATE TABLE employee (
      ->   ID INT(2) auto_increment primary key,
      ->   First_name VARCHAR(20),
      ->   Last_name VARCHAR(30),
      ->   Start_date DATE,
      ->   Salary int(6),
      ->   city VARCHAR(20),
      ->   description VARCHAR(20)
      -> );
    Query OK, 0 rows affected (0.02 sec)

    mysql>
    mysql> desc employee;
    +-------------+-------------+------+-----+---------+----------------+
    | Field    | Type    | Null | Key | Default | Extra     |
    +-------------+-------------+------+-----+---------+----------------+
    | ID     | int(2)   | NO  | PRI | NULL  | auto_increment |
    | First_name | varchar(20) | YES |   | NULL  |        |
    | Last_name  | varchar(30) | YES |   | NULL  |        |
    | Start_date | date    | YES |   | NULL  |        |
    | Salary   | int(6)   | YES |   | NULL  |        |
    | city    | varchar(20) | YES |   | NULL  |        |
    | description | varchar(20) | YES |   | NULL  |        |
    +-------------+-------------+------+-----+---------+----------------+
    7 rows in set (0.00 sec)

以上就是对mysql desc 的资料整理,后续继续补充相关资料,谢谢大家对本站的支持!

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