mysql基础教程 -- 数据库的基本操作

实验环境

mysql版本：5.7.22
操作系统：ubuntu-16.04-x64

创建数据库

命令格式：
CREATE DATABASE db_name
db_name为要创建的数据库名。
例：

mysql> CREATE DATABASE school;                        │                                                     
Query OK, 1 row affected (0.00 sec)                   │                                                     
                                                      │                                                     
mysql> SHOW DATABASES;                                │                                                     
+--------------------+                                │                                                     
| Database           |                                │                                                     
+--------------------+                                │                                                     
| information_schema |                                │                                                     
| mysql              |                                │                                                     
| performance_schema |                                │                                                     
| school             |                                │                                                     
| sys                |                                │                                                     
| test               |                                │                                                     
| test1              |                                │                                                     
+--------------------+                                │                                                     
7 rows in set (0.00 sec)          

查看数据库

• 切换数据库
  命令格式：USE db_name
  db_name为要切换的数据库名
  例：

  mysql> USE test;                                                         
  Database changed
  

• 查看所有数据库
  命令格式：SHOW DATABASES；
  例：

  mysql> SHOW DATABASES;                                                  
  +--------------------+                                │                                                     
  | Database           |                                │                                                     
  +--------------------+                                │                                                     
  | information_schema |                                │                                                     
  | mysql              |                                │                                                     
  | performance_schema |                                │                                                     
  | sys                |                                │                                                     
  | test               |                                │                                                     
  | test1              |                                │                                                     
  +--------------------+                                │                                                     
  6 rows in set (0.00 sec) 
  

• 查看数据创建语句
  SHOW CREATE DATABASE db_name
  db_name为要查看的数据库名
  例：

  mysql> SHOW CREATE DATABASE test;                                               
  +----------+------------------------------------------│                                                     
  -----------------------+                              │                                                     
  | Database | Create Database                          │                                                     
                         |                              │                                                     
  +----------+------------------------------------------│                                                     
  -----------------------+                              │                                                     
  | test     | CREATE DATABASE `test` /*!40100 DEFAULT C│                                                     
  HARACTER SET latin1 */ |                              │                                                     
  +----------+------------------------------------------│                                                     
  -----------------------+                              │                                                     
  1 row in set (0.00 sec)
  

• 查看当前使用的数据库
  命令格式：SELECT DATABASE()
  例：

  mysql> SELECT DATABASE();                             
  +------------+                                        │                                                     
  | DATABASE() |                                        │                                                     
  +------------+                                        │                                                     
  | test       |                                        │                                                     
  +------------+                                        │                                                     
  1 row in set (0.00 sec)  
  

删除数据库

命令格式：
DROP DATABASE db_name
db_name为要删除的数据库名。
例：

mysql> DROP DATABASE school;                                                
Query OK, 0 rows affected (0.00 sec)

存储引擎

• 查看数据库支持的所有存储引擎
  命令格式：SHOW ENGINES
  例：

   mysql> SHOW ENGINES;
  +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
  | Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
  +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
  | MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
  | CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
  | MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
  | BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
  | PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
  | MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
  | ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
  | InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
  | FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       |
  +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
  9 rows in set (0.00 sec)
  

• 查看默认存储引擎
  命令格式：SHOW VARIABLES LIKE ‘%storage_engine%’;
  例：

  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 (0.00 sec)