[email protected] ~]# mysql -uroot -pzaq12wsx #入库
mysql> show databases; #查库
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 24
Current database: *** NONE ***
+--------------------+
| Database |
+--------------------+
| information_schema |
| discuz |
| mysql |
| test |
+--------------------+
4 rows in set (0.04 sec)
mysql> use mysql #切换库
No connection. Trying to reconnect...
Connection id: 25
Current database: *** NONE ***
Database changed
#切换了库以后，我们如怎么确认我们当前是在哪个库下
mysql> select database();# 查看当前数据库的命令
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 28
Current database: discuz
+------------+
| database() |
+------------+
| discuz |
+------------+
1 row in set (0.00 sec)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mysql> select version();# 查看软件的版本
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 30
Current database: discuz
+------------+
| version() |
+------------+
| 5.1.73-log |
+------------+
1 row in set (0.00 sec)
——————————————————————————————————————————————
库--> 表--> 行 --> 字段
mysql> show tables; # 查库
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 31
Current database: discuz
+-----------------------------------+
| Tables_in_discuz |
+-----------------------------------+
| pre_common_admincp_cmenu |
| pre_common_admincp_group |
| pre_common_admincp_member |#下略，太多
| pre_common_admincp_perm |
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
查看表的字段
mysql> desc pre_ucenter_vars; #查看表的字段
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 32
Current database: discuz
+-------+-----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-----------+------+-----+---------+-------+
| name | char(32) | NO | PRI | | |
| value | char(255) | NO | | | |
+-------+-----------+------+-----+---------+-------+
2 rows in set (0.02 sec)
mysql> show create table pre_ucenter_vars\G; #查询表的创建语句
*************************** 1. row ***************************
Table: pre_ucenter_vars
Create Table: CREATE TABLE `pre_ucenter_vars` (
`name` char(32) NOT NULL DEFAULT ‘‘,
`value` char(255) NOT NULL DEFAULT ‘‘,
PRIMARY KEY (`name`)
) ENGINE=MEMORY DEFAULT CHARSET=gbk
1 row in set (0.00 sec)
ERROR:
No query specified
##############################################################################################
手动创建一个库
mysql> create database obird; # 创建库名
mysql> use obird; # 进入创建库
mysql> create table tb1 (`id` int(4), `name` char(40)) ENGINE=MyISAM DEFAULT CHARSET=gbk;
#创建表名 tb1,表内的字段 int(长度是4位)，char(最长40)，ENGINE ,字符集=gbk
mysql> show tables;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 41
Current database: obird
+-----------------+
| Tables_in_obird |
+-----------------+
| tb1 |
+-----------------+
1 row in set (0.00 sec)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mysql> desc tb1;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 42
Current database: obird
+-------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| id | int(4) | YES | | NULL | |
| name | char(40) | YES | | NULL | |
+-------+----------+------+-----+---------+-------+
2 rows in set (0.00 sec)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mysql> show create table tb1\G;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 44
Current database: obird
*************************** 1. row ***************************
Table: tb1
Create Table: CREATE TABLE `tb1` (
`id` int(4) DEFAULT NULL,
`name` char(40) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=gbk
1 row in set (0.00 sec)
ERROR:
No query specified
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
在表内插入数据
mysql> insert into tb1 values(1,‘aming‘);
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 45
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1; # 查询
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 46
Current database: obird
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
+------+-------+
1 row in set (0.00 sec)
继续插入
mysql> insert into tb1 values(2,‘linux‘);
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 47
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1; #再次查询
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 48
Current database: obird
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
+------+-------+
2 rows in set (0.00 sec)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
只插一个字段
mysql> insert into tb1 (`id`) values(2);
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 49
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1;
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
| 2 | NULL |# 只插入一个字段ID，name 此处是空的
+------+-------+
3 rows in set (0.00 sec)
mysql> insert into tb1 (`name`) values(‘test‘);
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 50
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1;
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
| 2 | NULL |
| NULL | test |# 只插入name ,ID 是空
+------+-------+
4 rows in set (0.00 sec)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
也可以花式插法，id&name 互换，但是要一一对应
mysql> insert into tb1 (`name`,`id`) values(‘77‘,6);
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 51
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1;
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
| 2 | NULL |
| NULL | test |
| 6 | 77 |
+------+-------+
5 rows in set (0.00 sec)
##############################################################################################
更新一条数据
mysql> update tb1 set id=8 where name = ‘77‘; #name = 77 的只有一行，改成了 “8”
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 52
Current database: obird
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from tb1;
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
| 2 | NULL |
| NULL | test |
| 8 | 77 |
+------+-------+
5 rows in set (0.00 sec)
删除一行
mysql> delete from tb1 where name=‘77‘;# 删除指定的一行 77
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 54
Current database: obird
Query OK, 1 row affected (0.00 sec)
mysql> select * from tb1;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 57
Current database: obird
+------+-------+
| id | name |
+------+-------+
| 1 | aming |
| 2 | linux |
| 2 | NULL |
| NULL | test |
+------+-------+ # 查询不到 77 的行
4 rows in set (0.00 sec)
清空一张表
mysql> truncate table obird.tb1; #清空一张表
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 59
Current database: obird
Query OK, 0 rows affected (0.00 sec)
mysql> select * from tb1; # 表已经空了
Empty set (0.00 sec)
干掉整张表
mysql> drop table tb1; #语法
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 60
Current database: obird
Query OK, 0 rows affected (0.00 sec)
mysql> select * from tb1;
ERROR 1146 (42S02): Table ‘obird.tb1‘ doesn‘t exist #报错表已经不存在
干掉 obird 这个库
mysql> show databases; #查询，obird 这个库是存在的
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 61
Current database: obird
+--------------------+
| Database |
+--------------------+
| information_schema |
| discuz |
| mysql |
| obird |
| test |
+--------------------+
5 rows in set (0.00 sec)
mysql> drop database obird; # 干掉库的语法
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 62
Current database: obird
Query OK, 0 rows affected (0.01 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| discuz |
| mysql |
| test |#再查询，obird 已经不在了。
+--------------------+
4 rows in set (0.00 sec)
##############################################################################################