数据库的创建应用
mysql> create database mingzi;
Query OK, 1 row affected (0.00 sec)
//创建
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mingzi |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.01 sec)
//查看
mysql> use mingzi;
Database changed
//进入数据库
mysql> DROP DATABASE IF EXISTS mingzi;
Query OK, 0 rows affected (0.00 sec)
//数据库的删除表的基本操作应用
mysql> create table wsm(id int(11) primary key auto_increment,name varchar(100) not null,age tinyint(4));
Query OK, 0 rows affected (0.00 sec)
//创建一张表 往里面输入数据
mysql> desc wsm;
+-------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(100) | NO | | NULL | |
| age | tinyint(4) | YES | | NULL | |
+-------+--------------+------+-----+---------+----------------+
3 rows in set (0.05 sec)
//查看这张表的结构
mysql> show tables;
+------------------+
| Tables_in_mingzi |
+------------------+
| wsm |
+------------------+
1 row in set (0.00 sec)
//查看这张表
mysql> drop table wsm;
Query OK, 0 rows affected (0.01 sec)
//表的删除查看命令SHOW
//字符集查看
mysql> show character set;
+----------+---------------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+----------+---------------------------------+---------------------+--------+
| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 |
| dec8 | DEC West European | dec8_swedish_ci | 1 |
| cp850 | DOS West European | cp850_general_ci | 1 |
| hp8 | HP West European | hp8_english_ci | 1 |
| koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 |
| latin1 | cp1252 West European | latin1_swedish_ci | 1 |
| latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 |
| swe7 | 7bit Swedish | swe7_swedish_ci | 1 |
| ascii | US ASCII | ascii_general_ci | 1 |
| ujis | EUC-JP Japanese | ujis_japanese_ci | 3 |
| sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 |
| hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 |
| tis620 | TIS620 Thai | tis620_thai_ci | 1 |
| euckr | EUC-KR Korean | euckr_korean_ci | 2 |
| koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 |
| gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 |
| greek | ISO 8859-7 Greek | greek_general_ci | 1 |
| cp1250 | Windows Central European | cp1250_general_ci | 1 |
| gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 |
| latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 |
| armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 |
| utf8 | UTF-8 Unicode | utf8_general_ci | 3 |
| ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 |
| cp866 | DOS Russian | cp866_general_ci | 1 |
| keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 |
| macce | Mac Central European | macce_general_ci | 1 |
| macroman | Mac West European | macroman_general_ci | 1 |
| cp852 | DOS Central European | cp852_general_ci | 1 |
| latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 |
| utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 |
| cp1251 | Windows Cyrillic | cp1251_general_ci | 1 |
| utf16 | UTF-16 Unicode | utf16_general_ci | 4 |
| utf16le | UTF-16LE Unicode | utf16le_general_ci | 4 |
| cp1256 | Windows Arabic | cp1256_general_ci | 1 |
| cp1257 | Windows Baltic | cp1257_general_ci | 1 |
| utf32 | UTF-32 Unicode | utf32_general_ci | 4 |
| binary | Binary pseudo charset | binary | 1 |
| geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 |
| cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 |
| eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 |
| gb18030 | China National Standard GB18030 | gb18030_chinese_ci | 4 |
+----------+---------------------------------+---------------------+--------+
41 rows in set (0.00 sec)
//查看所有的字符集//查看数据库当前所有的存储引擎
mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine | Support | Comment | Transactions | XA | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO |
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO |
| BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO |
| MyISAM | YES | MyISAM storage engine | NO | NO | NO |
| CSV | YES | CSV storage engine | NO | NO | NO |
| ARCHIVE | YES | Archive storage engine | NO | NO | NO |
| PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO |
| FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
9 rows in set (0.00 sec)
//查看每张表是怎么创建出来的
mysql> SHOW CREATE TABLE wsm;
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table | Create Table |
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| wsm | CREATE TABLE `wsm` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(100) NOT NULL,
`age` tinyint(4) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)
//查看每张表的状态
mysql> SHOW TABLE STATUS LIKE 'student%'\G;
*************************** 1. row ***************************
Name: student
Engine: InnoDB
Version: 10
Row_format: Dynamic
Rows: 0
Avg_row_length: 0
Data_length: 16384
Max_data_length: 0
Index_length: 0
Data_free: 0
Auto_increment: NULL
Create_time: 2022-04-20 16:08:16
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment:
*************************** 2. row ***************************
Name: student1
Engine: InnoDB
Version: 10
Row_format: Dynamic
Rows: 0
Avg_row_length: 0
Data_length: 16384
Max_data_length: 0
Index_length: 0
Data_free: 0
Auto_increment: NULL
Create_time: 2022-04-20 16:09:54
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment:
*************************** 3. row ***************************
Name: student2
Engine: InnoDB
Version: 10
Row_format: Dynamic
Rows: 0
Avg_row_length: 0
Data_length: 16384
Max_data_length: 0
Index_length: 0
Data_free: 0
Auto_increment: NULL
Create_time: 2022-04-20 16:10:36
Update_time: NULL
Check_time: NULL
Collation: latin1_swedish_ci
Checksum: NULL
Create_options:
Comment:
3 rows in set (0.00 sec)
ERROR:
No query specified
获取帮助
mysql> help create database;
Name: 'CREATE DATABASE'
Description:
Syntax:
CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name
[create_option] ...
create_option: [DEFAULT] {
CHARACTER SET [=] charset_name
| COLLATE [=] collation_name
}
CREATE DATABASE creates a database with the given name. To use this
statement, you need the CREATE privilege for the database. CREATE
SCHEMA is a synonym for CREATE DATABASE.
URL: https://dev.mysql.com/doc/refman/5.7/en/create-database.html
mysql>
mysql> help create table;
DML操作
查看表中的内容
insert语句与select updata语句的结合运用
mysql> desc student;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | int(11) | NO | | NULL | |
| name | varchar(30) | YES | | NULL | |
| age | tinyint(4) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
3 rows in set (0.00 sec)
mysql> select * from student;
Empty set (0.00 sec)
在空表中插入内容
mysql> insert student value(1,'tom',15);
Query OK, 1 row affected (0.00 sec)
mysql> select * from student;
+----+------+------+
| id | name | age |
+----+------+------+
| 1 | tom | 15 |
+----+------+------+
1 row in set (0.00 sec)
mysql> insert info1(name,age) values('tom',15),('jerry',16);
Query OK, 2 rows affected (0.00 sec)
Records: 2 Duplicates: 0 Warnings: 0
mysql> select * from info1;
+----+-------+------+
| id | name | age |
+----+-------+------+
| 1 | tom | 15 |
| 2 | jerry | 16 |
+----+-------+------+
2 rows in set (0.00 sec)
//自动排序插入//修改表里的内容
mysql> select * from info1;
+----+-------+------+
| id | name | age |
+----+-------+------+
| 1 | tom | 15 |
| 2 | jerry | 16 |
+----+-------+------+
2 rows in set (0.00 sec)
mysql> update info1 set age = 18 where id = 2;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from info1;
+----+-------+------+
| id | name | age |
+----+-------+------+
| 1 | tom | 15 |
| 2 | jerry | 18 |
+----+-------+------+
2 rows in set (0.00 sec)
//只显示名字和年龄
mysql> select name,age from info1;
+-------+------+
| name | age |
+-------+------+
| tom | 15 |
| jerry | 18 |
+-------+------+
2 rows in set (0.00 sec)
//查找表中大于或等于某位数字的人
mysql> insert info1(name,age) values('zhangsan',16),('wangwu',19),('qianliu',220),('zhangsan',20);
Query OK, 4 rows affected (0.00 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> insert info1(name) value('lisi');
Query OK, 1 row affected (0.00 sec)
mysql> select * from info1;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 1 | tom | 15 |
| 2 | jerry | 18 |
| 3 | zhangsan | 16 |
| 4 | wangwu | 19 |
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
| 7 | lisi | NULL |
+----+----------+------+
7 rows in set (0.00 sec)
mysql> select * from info1 where age > 19;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
+----+----------+------+
2 rows in set (0.00 sec)
mysql> select * from info1 where age >=19;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 4 | wangwu | 19 |
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
+----+----------+------+
3 rows in set (0.00 sec)
between某位数到某位数直接的
mysql> select * from info1 where age between 18 and 20;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 2 | jerry | 18 |
| 4 | wangwu | 19 |
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
+----+----------+------+
4 rows in set (0.00 sec)
not取反
mysql> select * from info1 where not age = 20;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 1 | tom | 15 |
| 2 | jerry | 18 |
| 3 | zhangsan | 16 |
| 4 | wangwu | 19 |
+----+----------+------+
4 rows in set (0.00 sec)
根据年龄排序
mysql> select * from info1 order by age;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 7 | lisi | NULL |
| 1 | tom | 15 |
| 3 | zhangsan | 16 |
| 2 | jerry | 18 |
| 4 | wangwu | 19 |
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
+----+----------+------+
7 rows in set (0.00 sec)
//正序
mysql> select * from info1 order by age desc;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
| 4 | wangwu | 19 |
| 2 | jerry | 18 |
| 3 | zhangsan | 16 |
| 1 | tom | 15 |
| 7 | lisi | NULL |
+----+----------+------+
7 rows in set (0.00 sec)
//倒序
mysql> select * from info1 order by age desc limit 1;
+----+---------+------+
| id | name | age |
+----+---------+------+
| 5 | qianliu | 20 |
+----+---------+------+
1 row in set (0.00 sec)
mysql> select name from info1 order by age desc limit 1;
+---------+
| name |
+---------+
| qianliu |
+---------+
1 row in set (0.00 sec)
//取出年龄最小的
mysql> select * from info1 order by age desc limit 1,1;
+----+---------+------+
| id | name | age |
+----+---------+------+
| 5 | qianliu | 20 |
+----+---------+------+
1 row in set (0.00 sec)
//跳过一个在取一个
delete删除表中的内容表格却存在
mysql> select * from info1;
+----+----------+------+
| id | name | age |
+----+----------+------+
| 1 | tom | 15 |
| 2 | jerry | 18 |
| 3 | zhangsan | 16 |
| 4 | wangwu | 19 |
| 5 | qianliu | 20 |
| 6 | zhangsan | 20 |
| 7 | lisi | NULL |
+----+----------+------+
7 rows in set (0.00 sec)
mysql> delete from info1 where id = 8;
Query OK, 0 rows affected (0.00 sec)
//删除第8行内容
mysql> delete from info1;
Query OK, 7 rows affected (0.00 sec)
mysql> select * from info1;
Empty set (0.00 sec)
//清空整张表
mysql> insert info1(name,age) value('tom',15);
Query OK, 1 row affected (0.00 sec)
mysql> select * from info1;
+----+------+------+
| id | name | age |
+----+------+------+
| 8 | tom | 15 |
+----+------+------+
1 row in set (0.00 sec)
//再次向表中插入内容一删除结尾的一行开始truncate语句删除表中内容表也存在
mysql> truncate table info1;
Query OK, 0 rows affected (0.01 sec)
mysql> insert info1(name,age) value('tom',15);
Query OK, 1 row affected (0.00 sec)
mysql> select * from info1;
+----+------+------+
| id | name | age |
+----+------+------+
| 1 | tom | 15 |
+----+------+------+
1 row in set (0.00 sec)
//truncate删除再次插入新的内容从第一列开始DCL操作
3.1创建授权grant
权限类型(priv_type)
指定要操作的对象db_name.table_name
| 表示方式 | 意义 |
|---|---|
| *.* | 所有库的所有表 |
| db_name | 指定库的所有表 |
| db_name.table_name | 指定库的指定表 |
| 权限类型 | 代表什么？ |
|---|---|
| ALL | 所有权限 |
| SELECT | 读取内容的权限 |
| INSERT | 插入内容的权限 |
| UPDATE | 更新内容的权限 |
| DELETE | 删除内容的权限 |
授权给用户
mysql> grant all on *.* to 'siming'@'localhost' identified by 'Siming540..';
Query OK, 0 rows affected, 1 warning (0.00 sec)
//创建一个siming用户给他授权
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
//刷新一下
mysql> SHOW GRANTS;
+---------------------------------------------------------------------+
| Grants for root@localhost |
+---------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION |
+---------------------------------------------------------------------+
2 rows in set (0.00 sec)
//查看当前登录账户
mysql> show grants for 'siming'@'localhost';
+-----------------------------------------------------+
| Grants for siming@localhost |
+-----------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'siming'@'localhost' |
+-----------------------------------------------------+
1 row in set (0.00 sec)
//查看siming用户的权限状态取消授权
mysql> revoke select on *.* from 'siming'@'localhost';
Query OK, 0 rows affected (0.00 sec)
//取消权限
