千家信息网

操作MySQL的基本命令有哪些

发表于:2024-11-18 作者:千家信息网编辑
千家信息网最后更新 2024年11月18日,本篇文章给大家主要讲的是关于操作MySQL的基本命令有哪些的内容,感兴趣的话就一起来看看这篇文章吧,相信看完操作MySQL的基本命令有哪些对大家多少有点参考价值吧。操作系统:CentOS数据库系统:M
千家信息网最后更新 2024年11月18日操作MySQL的基本命令有哪些

本篇文章给大家主要讲的是关于操作MySQL的基本命令有哪些的内容,感兴趣的话就一起来看看这篇文章吧,相信看完操作MySQL的基本命令有哪些对大家多少有点参考价值吧。

操作系统:CentOS

数据库系统:MySQL

[root@sky9896~]# mysql -h localhost -P 3306 -uroot -p #注意端口号前的P是大小

mysql>select version(),current_date; #检索当前数据库版本和当前时间

+----------------+--------------+

|version() | current_date |

+----------------+--------------+

|5.5.52-cll-lve | 2017-08-09 |

+----------------+--------------+

1row in set (0.00 sec)

mysql>use employees #打开数据库

Databasechanged

mysql>select database(); #查询当前数据库

+------------+

|database() |

+------------+

|employees |

+------------+

1row in set (0.00 sec)

mysql>show tables; #显示该数据库当中的所有表

+---------------------+

|Tables_in_employees |

+---------------------+

|departments |

|dept_emp |

|dept_manager |

|employees |

|salaries |

|titles |

+---------------------+

6rows in set (0.00 sec)

mysql>create table employees_2( #建表

-> emp_no int(11) NOT NULL,

-> birth_date date NOT null,

-> first_name varchar(14) not null,

-> last_name varchar(16) not null,

-> gender enum('M','F') not null,

-> hire_date date not null,

-> primary key(emp_no)

-> )engine=innodb default charset=latin1;

QueryOK, 0 rows affected (0.19 sec)

mysql>desc employees_2; #显示表结构

+------------+---------------+------+-----+---------+-------+

|Field | Type | Null | Key | Default | Extra |

+------------+---------------+------+-----+---------+-------+

|emp_no | int(11) | NO | PRI | NULL | |

|birth_date | date | NO | | NULL | |

|first_name | varchar(14) | NO | | NULL | |

|last_name | varchar(16) | NO | | NULL | |

|gender | enum('M','F') | NO | | NULL | |

|hire_date | date | NO | | NULL | |

+------------+---------------+------+-----+---------+-------+

6rows in set (0.02 sec)

mysql>create table t1(a integer,b char(10));

QueryOK, 0 rows affected (0.11 sec)

mysql>show tables;

+---------------------+

|Tables_in_employees |

+---------------------+

|departments |

|dept_emp |

|dept_manager |

|employees |

|employees_2 |

|salaries |

|t1 |

|titles |

+---------------------+

8rows in set (0.00 sec)

mysql>alter table t1 rename t2; #修改表名

QueryOK, 0 rows affected (0.05 sec)

mysql>show tables;

+---------------------+

|Tables_in_employees |

+---------------------+

|departments |

|dept_emp |

|dept_manager |

|employees |

|employees_2 |

|salaries |

|t2 |

|titles |

+---------------------+

8rows in set (0.00 sec)

mysql>desc t2;

+-------+----------+------+-----+---------+-------+

|Field | Type | Null | Key | Default |Extra |

+-------+----------+------+-----+---------+-------+

|a | int(11) | YES | | NULL | |

|b | char(10) | YES | |NULL | |

+-------+----------+------+-----+---------+-------+

2rows in set (0.00 sec)

mysql> alter table t2 modify a tinyint notnull,change b c char(20); #修改列表

QueryOK, 0 rows affected (0.25 sec)

Records:0 Duplicates: 0 Warnings: 0

mysql>desc t2;

+-------+------------+------+-----+---------+-------+

|Field | Type | Null | Key | Default| Extra |

+-------+------------+------+-----+---------+-------+

|a | tinyint(4) | NO | | NULL | |

|c | char(20) | YES | | NULL | |

+-------+------------+------+-----+---------+-------+

2rows in set (0.00 sec)

ysql>alter table t2 add d timestamp;

QueryOK, 0 rows affected (0.19 sec)

Records:0 Duplicates: 0 Warnings: 0

mysql>desc t2;

+-------+------------+------+-----+-------------------+-----------------------------+

|Field | Type | Null | Key |Default | Extra |

+-------+------------+------+-----+-------------------+-----------------------------+

|a | tinyint(4) | NO | | NULL | |

|c | char(20) | YES | | NULL | |

|d | timestamp | NO | | CURRENT_TIMESTAMP | on updateCURRENT_TIMESTAMP |

+-------+------------+------+-----+-------------------+-----------------------------+

3rows in set (0.00 sec)

mysql>alter table t2 add index(d),add index(a); #添加索引

mysql>show keys from t2;

mysql>insert into employees(emp_no,birth_date,first_name,last_name,gender,hire_date)values('1111112','2017-8-9','wu','haiming','M','2017-08-09');

QueryOK, 1 row affected (0.09 sec)

mysql>select * from employees where emp_no=1111112;

+---------+------------+------------+-----------+--------+------------+

|emp_no | birth_date | first_name |last_name | gender | hire_date |

+---------+------------+------------+-----------+--------+------------+

|1111112 | 2017-08-09 | wu |haiming | M | 2017-08-09 |

+---------+------------+------------+-----------+--------+------------+

1row in set (0.00 sec)

以上关于操作MySQL的基本命令有哪些详细内容,对大家有帮助吗?如果想要了解更多相关,可以继续关注我们的行业资讯板块。

0