数据库的基本操作

创建数据库
mysql> SHOW DATABASES;
+——————–+
| Database |
+——————–+
| information_schema |
| mysql |
| performance_schema |
| sys |
+——————–+
4 rows in set (0.35 sec)
mysql> CREATE DATABASE test_db;
Query OK, 1 row affected (0.01 sec)
mysql> show create database tese_db;
ERROR 1049 (42000): Unknown database ‘tese_db‘
mysql> show create database test_db;
+———-+——————————————————————+
| Database | Create Database |
+———-+——————————————————————+
| test_db | CREATE DATABASE test_db /!40100 DEFAULT CHARACTER SET utf8 / |
+———-+——————————————————————+
1 row in set (0.00 sec)
删除数据库


mysql> DROP DATABASE test_db;

Query OK, 0 rows affected (0.09 sec)


数据库存储引擎

mysql> SHOW ENGINES\G


1. row

Engine: InnoDB

Support: DEFAULT

Comment: Supports transactions, row-level locking, and foreign keys

Transactions: YES

XA: YES

Savepoints: YES


2. row

Engine: MRG_MYISAM

Support: YES

Comment: Collection of identical MyISAM tables

Transactions: NO

XA: NO

Savepoints: NO


3. row

Engine: MEMORY

Support: YES

Comment: Hash based, stored in memory, useful for temporary tables

Transactions: NO

XA: NO

Savepoints: NO


4. row

Engine: BLACKHOLE

Support: YES

Comment: /dev/null storage engine (anything you write to it disappears)

Transactions: NO

XA: NO

Savepoints: NO


5. row

Engine: MyISAM

Support: YES

Comment: MyISAM storage engine

Transactions: NO

XA: NO

Savepoints: NO


6. row

Engine: CSV

Support: YES

Comment: CSV storage engine

Transactions: NO

XA: NO

Savepoints: NO


7. row

Engine: ARCHIVE

Support: YES

Comment: Archive storage engine

Transactions: NO

XA: NO

Savepoints: NO


8. row

Engine: PERFORMANCE_SCHEMA

Support: YES

Comment: Performance Schema

Transactions: NO

XA: NO

Savepoints: NO


9. row

Engine: FEDERATED

Support: NO

Comment: Federated MySQL storage engine

Transactions: NULL

XA: NULL

Savepoints: NULL

9 rows in set (0.00 sec)


查看默认存储引擎

mysql> show variables like ‘default_storage_engine‘;

+————————+——–+

| Variable_name | Value |

+————————+——–+

| default_storage_engine | InnoDB |

+————————+——–+

1 row in set (0.00 sec)