掌握MySQL表结构查询命令(查看mysql表命令)

MySQL是世界上最流行的关系型数据库管理系统,它提供了一组有用的语句和函数来查询和操作数据库内部的数据表,表结构查询命令是其中之一,一般是用于查询和输出表结构信息的查询语句。本文介绍了一些常见的MySQL表结构查询命令,以帮助用户掌握这些命令操作,更好的管理MySQL数据库。

首先,我们可以使用desc命令来查看或验证MySQL表的结构,即表的所有列,以及每一列的数据类型等,下面是实际例子:

mysql> desc table;
+---------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+---------+------+-----+---------+-------+
| id | int(11) | NO | PRI | NULL | |
| name | char(20)| NO | | NULL | |
| content | varchar | YES | | NULL | |
+---------+---------+------+-----+---------+-------+
3 rows in set (0.00 sec)

其次,要查看表的索引,可以使用show indexes命令,它可以提供多少索引,以及每个索引名称,索引类型,唯一字段值等详细信息,如下:

mysql> show index from table;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| table | 0 | PRIMARY | 1 | id | A | 4 | NULL | NULL | | BTREE | | |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
1 row in set (0.00 sec)

再者,可以使用show table status[from db_name]命令,它可以提供数据表的状态,如表的字符编码,默认存储引擎等信息,如下:

mysql> show table status from db_name;
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+-----------------+------------+-----------------+----------+----------------+---------+
| Name | Engine | Version | Row_format | Rows | Avg_row_length | Data_length | Max_data_length | Index_length | Data_free | Auto_increment | Create_time | Update_time | Check_time | Collation | Checksum | Create_options | Comment |
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+-----------------+------------+-----------------+----------+----------------+---------+
| table | MyISAM | 10 | Dynamic | 0 | 0 | 163840 | 0 | 16384 | 0 | NULL | 2019-12-24 10:15:13 | NULL | NULL | utf8_bin | NULL | | |
+--------+--------+---------+------------+------+----------------+-------------+-----------------+--------------+-----------+----------------+---------------------+-------------+-----------------+------------+-----------------+----------+----------------+---------+
1 row in set (0.00 sec)

最后,我们可以使用show create table command来查看一个表的创建语句,它可以提供如表的字符编码,存储引擎,索引信息等详细内容,如下:

mysql> show create table table;
+-------+------------------------------------------+
| Table | Create Table |
+-------+------------------------------------------+
| table | CREATE TABLE `table` (
`id` int(11) NOT NULL,
`name` char(20) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+-------+------------------------------------------+
1 row in set (0.00 sec)

掌握MySQL表结构查询命令可以让用户更加熟练、高效的查询并操作MySQL数据库,本文介绍了几个常用的MySQL表结构查询命令,相信大家在实际操作中也可以有所参考,让自己更好地掌握MySQL表结构查询命令。


数据运维技术 » 掌握MySQL表结构查询命令(查看mysql表命令)