mysql控制台的一些技巧,显示,输入换行，语法正则等

注释：
以/**注释内容**/

mysql> /**列出所有的数据库**/ show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db_springcloud     |
| mysql              |
| performance_schema |
| test               |
| wordpress          |
| xinyu              |
| xinyu2             |
| zabbix             |
+--------------------+
9 rows in set (0.00 sec)

###注释是从‘#’字符到行尾

mysql> #这里是注释，到行尾都是注释，所以后面的命令不执行 showdatabases;
mysql> 

如果遇到很长的sql语句的话，在控制台为了阅读方便，我们可以使用\，使之继续输入；

mysql> show \
    -> databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| db_springcloud     |
| mysql              |
| performance_schema |
| test               |
| wordpress          |
| xinyu              |
| xinyu2             |
| zabbix             |
+--------------------+
9 rows in set (0.00 sec)
mysql>

也支持正则like查询

mysql> show databases like '%inyu%';
+-------------------+
| Database (%inyu%) |
+-------------------+
| xinyu             |
| xinyu2            |
+-------------------+
2 rows in set (0.00 sec)

同理，show tables也支持，用from语法，可以少一步use 数据库

mysql> show tables from test;
+----------------+
| Tables_in_test |
+----------------+
| hbk            |
+----------------+
1 row in set (0.00 sec)
mysql> show tables from test like '%b%';

+----------------------+

| Tables_in_test (%b%) |

+----------------------+

| hbk                  |

+----------------------+

1 row in set (0.00 sec)

查看表定义，可以使用show create table 表名 \G
\G只是显示的格式更好看而已，也可以使用describe语法

mysql> use test;
mysql> show create table hbk \G;
*************************** 1. row ***************************
       Table: hbk
Create Table: CREATE TABLE `hbk` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
ERROR:

No query specified
mysql> describe hbk;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | varchar(20) | NO   |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

2 rows in set (0.00 sec)
mysql> desc hbk;

+-------+-------------+------+-----+---------+----------------+

| Field | Type        | Null | Key | Default | Extra          |

+-------+-------------+------+-----+---------+----------------+

| id    | int(11)     | NO   | PRI | NULL    | auto_increment |

| name  | varchar(20) | NO   |     | NULL    |                |

+-------+-------------+------+-----+---------+----------------+

2 rows in set (0.01 sec)

知识点注意：
数据名的最大长度64字节
表名的最大长度64字节
列名的最大长度64字节
索引名的最大长度64字节
别名的最大长度255字节

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