一、查看Mysql版本
//方式一
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.22 |
+-----------+
1 row in set (0.00 sec)
//方式二
mysql> select @@version ;
+-----------+
| @@version |
+-----------+
| 5.7.22 |
+-----------+
1 row in set (0.00 sec)
//方式三
mysql> status
--------------
mysql Ver 14.14 Distrib 5.7.22, for Win64 (x86_64)
Connection id: 21
Current database:
Current user: root@localhost
SSL: Not in use
Using delimiter: ;
Server version: 5.7.22 MySQL Community Server (GPL)
Protocol version: 10
Connection: localhost via TCP/IP
Server characterset: utf8mb4
Db characterset: utf8mb4
Client characterset: utf8mb4
Conn. characterset: utf8mb4
TCP port: 3306
Uptime: 179 days 16 hours 46 sec
Threads: 16 Questions: 92 Slow queries: 0 Opens: 29 Flush tables: 1
Open tables: 20 Queries per second avg: 1.826
--------------
mysql>
二、存储引擎
mysql已提供的存储引擎:
mysql> show engines;
//mysql当前默认的存储引擎:
mysql> show variables like '%storage_engine%';
+----------------------------------+--------+
| Variable_name | Value |
+----------------------------------+--------+
| default_storage_engine | InnoDB |
| default_tmp_storage_engine | InnoDB |
| disabled_storage_engines | |
| internal_tmp_disk_storage_engine | InnoDB |
+----------------------------------+--------+
4 rows in set, 1 warning (0.00 sec)
三、查看用户
1、查看Mysql的当前用户
mysql> SELECT USER ();
+-----------------------+
| USER () |
+-----------------------+
| root@localhost |
+-----------------------+
1 row in set (0.00 sec)
mysql>
2、查看所有用户
mysql> SELECT user,host FROM mysql.user;
+--------------------+---------------+
| user | host |
+--------------------+---------------+
| test | % |
| test | localhost |
| aser | 192.168.1.64 |
| aser | localhost |
| mysql.session | localhost |
| mysql.sys | localhost |
| root | localhost |
+--------------------+---------------+
7 rows in set (0.00 sec)
四、查看数据库及表信息
//1、显示数据库列表。
show databases;
//2、显示库中的数据表:
use mysql;
show tables;
//3、显示数据表的结构:
describe 表名;
# 查看当前连接的数据库
mysql> select database();
+------------+
| database() |
+------------+
| testdb |
+------------+
1 row in set (0.00 sec)
mysql>
五、数据库运行状态的基本命令
show full processlist; # 查询数据库连接
show variables like '%max_connections%';# 查看最大连接数量
show status like '%Max_used_connections%'; # 查询数据库使用过的最大连接
show status like '%Threads_connected%';# 当前连接数
show status like '%table_lock%';# 表锁定
show status like 'innodb_row_lock%';# 行锁定
show status like '%qcache%'; # 查询缓存情况
show variables like '%timeout%';# 查看超时时间
show variables like 'log_%'; # 查看日志是否启动