mysql控制台的一些技巧,顯示,輸入換行，語法正則等

注釋：
以/**注釋內容**/

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

   
   
   
           

###注釋是從‘#’字符到行尾

mysql> #這里是注釋，到行尾都是注釋，所以后面的命令不執行 showdatabases;
mysql> 

   
   
   
           

如果遇到很長的sql語句的話，在控制台為了閱讀方便，我們可以使用\，使之繼續輸入；

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

   
   
   
           

也支持正則like查詢

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語法，可以少一步use 數據庫

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)

   
   
   
           

查看表定義，可以使用show create table 表名 \G
\G只是顯示的格式更好看而已，也可以使用describe語法

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)

   
   
   
           

知識點注意：
數據名的最大長度64字節
表名的最大長度64字節
列名的最大長度64字節
索引名的最大長度64字節
別名的最大長度255字節

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