如何在mysql中创建数据库与表

前面介绍了如何安装配置MYSQL以及设置ROOT密码等内容，接下来学习怎么创建一个新的数据库及表；首先确保MYSQL已经正常启动运行中，否则，手动把它启动，如以下命令：

# service mysqld start
or
# /etc/init.d/mysqld start

MYSQL正常启动之后，我们进入数据库进行操作：

# mysql -uroot -p

一、创建数据库

# 查看数据库

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| test |
+--------------------+
3 rows in set (0.00 sec)

# 新建数据

mysql> create database mydatabase;
Query OK, 1 row affected (0.00 sec)

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mydatabase |
| mysql |
| test |
+--------------------+
4 rows in set (0.00 sec)

二、创建表

# 进入mydatabase数据库

mysql> use mydatabase;
Database changed
# 查看表

mysql> show tables
Empty set (0.00 sec)
# 新建表

mysql> create table mytable(
-> name char(30),
-> phone char(10)
-> );
Query OK, 0 rows affected (0.01 sec)

mysql> show tables;
+----------------------+
| Tables_in_mydatabase |
+----------------------+
| mytable |
+----------------------+
1 row in set (0.00 sec)

# 更改表名

mysql> alter table mytable rename test1;
Query OK, 0 rows affected (0.00 sec)

mysql> show tables;
+----------------------+
| Tables_in_mydatabase |
+----------------------+
| test1 |
+----------------------+
1 row in set (0.00 sec)

三、表结构之增、删、改、查

# 增
mysql> alter table mytable add sex char(10);
Query OK, 3 rows affected (0.02 sec)
Records: 3 Duplicates: 0 Warnings: 0

# 删
mysql> alter table mytable drop sex;
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0

# 改
mysql> alter table mytable modify sex char(11);
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
或者
mysql> alter table mytable change sex sex char(11);
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
----------------------------------
mysql> alter table mytable change newsex sex char(11);
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0

# 查
mysql> desc mytable;
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| name | char(30) | YES | | NULL | |
| phone | char(11) | YES | | NULL | |
| sex | char(11) | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
3 rows in set (0.00 sec)2 rows in set (0.00 sec)