数据库ddl及dml的基本操作

Posted 2020-06-15

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主键:

PRIMARY KEY 主键   UNIQUE KEY 唯一键

DDL：   CREATE DATABASE  创建数据库    CREATE TABLE  创建表    CREATE USER  创建用户

DROP DATABASE  删除数据库   DROP TABLE  删除表    DROP USER  删除用户

GRANT  授权   REVOKE  取消授权    DML：    INSERT  插入数据    DELETE  删除数据    UPDATE  更新数据    SELECT  查询数据

管理数据库：   CREATE DATABASE DB_NAME;    DROP DATABASE DB_NAME;

SHOW DATABASES;

管理表：

CREATE TABLE [DB_NAME.]TABLE_NAME (COLUMN DEFINATION)   COLUMN DEFINATION:    (col1_name data_type [修饰符], col2_name data_type [修饰符])

查看表定义：   DESC TB_NAME

DROP TABLE TB_NAME;

管理用户：   CREATE USER [email protected] [IDENTIFIED BY ‘password‘];

HOST表示格式：

ip:  网络地址：

mysql的字符通配符：   %: 匹配任意长度的任意字符     _: 匹配任意单个字符

DROP USER [email protected];

GRANT 权限列表 ON DB_NAME.TB_NAME TO [email protected] [IDENTIFIED BY ‘new_pass‘];

权限列表：   ALL PRIVILEGES，可简写为ALL    DB_NAME：

*：所有库

TB_NAME：   *: 所有表

刷新授权表，以使得权限立即生效：   mysql> FLUSH PRIVILEGES;

REVOKE 权限列表 ON DB_NAME.DB_TABLE FROM [email protected];

DML:

插入数据：

INSERT INTO tb_name [(col1, col2,...)] VALUE|VALUES (val1, val2,...)[,(val1, val2,...)];

mysql> INSERT INTO students (Name,Age,Gender,Class) VALUES (‘jerry‘,43,‘m‘,‘class 2‘),(‘Ou Yangfeng‘,77,‘m‘,‘Hamopai‘);

查询数据：

SELECT 字段列表 FROM 表 WHERE 条件子句 ORDER BY 字段;

组合条件：   and    or    not

BETWEEN start_value AND end_value;

LIKE: 模糊匹配   Name LIKE O%;

RLIKE：模式匹配   Name RLIKE ‘^O.*$‘

删除数据：   DELETE FROM tb_name WHERE 条件子句 [LIMIT n];

更新数据：

UPDATE tb_name SET col1=new_value1 WHERE 条件子句;

mysql> create database zone; 创建zone数据库
Query OK, 1 row affected (0.00 sec)

mysql> drop database zone; 删除数据库
Query OK, 1 row affected (0.00 sec)

mysql> use dingchao; 使用数据库
Database changed

mysql> create table boss ( ID int unsigned not null unique key auto_increment,

Name char(10) not null, Age tinyint, Gender enum(‘N‘,‘M‘) not null, Gongzi char(15));
Query OK, 0 rows affected (0.08 sec) 创建表

mysql> insert into boss (Name,Age,Gender,GongZI) VALUE (‘sloary‘,‘22‘,‘N‘,‘4400‘),

(‘mara‘,‘35‘,‘M‘,‘3600‘),(‘jifu‘,‘77‘,‘N‘,‘5800‘); 插入数据
Query OK, 3 rows affected (0.00 sec)

mysql> select * from boss;
+----+--------+------+--------+--------+
| ID | Name   | Age | Gender | GongZI |
+----+--------+------+--------+--------+
| 1 | sloary |   22 | N      | 4400   |
| 2 | mara   |   35 | M      | 3600   |
| 3 | jifu   |   77 | N      | 5800   |
| 4 | lili   |   22 | N      | 3800   |
| 5 | boy    |   35 | M      | 2600   |
| 6 | tom    |   77 | M      | 3000   |
| 7 | mary   |   18 | N      | 6000   |
| 8 | king   |   28 | M      | 4600   |
| 9 | hellen |   30 | M      | 3000   |
+----+--------+------+--------+--------+
9 rows in set (0.00 sec)

mysql> select * from boss where Age > 22 ; 选择行查询年龄大于22岁的人
+----+--------+------+--------+--------+
| ID | Name   | Age | Gender | GongZI |
+----+--------+------+--------+--------+
| 2 | mara   |   35 | M      | 3600   |
| 3 | jifu   |   77 | N      | 5800   |
| 5 | boy    |   35 | M      | 2600   |
| 6 | tom    |   77 | M      | 3000   |
| 8 | king   |   28 | M      | 4600   |
| 9 | hellen |   30 | M      | 3000   |
+----+--------+------+--------+--------+
6 rows in set (0.00 sec)

mysql> select Name,Age,GongZI from boss where Age > 30; 查询年龄大于30岁人的工资

投影列选择行，记住前面多个字段要加 “，”
+------+------+--------+
| Name | Age | GongZI |
+------+------+--------+
| mara |   35 | 3600   |
| jifu |   77 | 5800   |
| boy |   35 | 2600   |
| tom |   77 | 3000   |
+------+------+--------+
4 rows in set (0.00 sec)

INSERT INTO box (Name,Age,Gender,GongZI) VALUE (‘sloary‘,‘22‘,‘N‘,‘4400‘),

(‘mara‘,‘35‘,‘M‘,‘3600‘),(‘jifu‘,‘77‘,‘N‘,‘5800‘); 插入数据

mysql> select Name,Age,GongZI from boss where Age > 30 order by Age,GongZI; 升序
+------+------+--------+
| Name | Age | GongZI |
+------+------+--------+
| boy |   35 | 2600   |
| mara |   35 | 3600   |
| tom |   77 | 3000   |
| jifu |   77 | 5800   |
+------+------+--------+
4 rows in set (0.00 sec)

mysql> select Name,Age,GongZI from boss where Age > 30 order by Age,GongZI desc; 降序
+------+------+--------+
| Name | Age | GongZI |
+------+------+--------+
| mara |   35 | 3600   |
| boy |   35 | 2600   |
| jifu |   77 | 5800   |
| tom |   77 | 3000   |
+------+------+--------+
4 rows in set (0.00 sec)

mysql> delete from boess; 这个命令慎用一删除整张表都被删除啦
Query OK, 0 rows affected (0.00 sec)

mysql> delete from boss where Age =22 ;
Query OK, 2 rows affected (0.00 sec) 一般跟where 条件使用

mysql> select * from boss;
+----+--------+------+--------+--------+
| ID | Name   | Age | Gender | GongZI |
+----+--------+------+--------+--------+
| 2 | mara   |   35 | M      | 3600   |
| 3 | jini   |   77 | N      | 5800   |
| 5 | boy    |   35 | M      | 2600   |
| 6 | tom    |   77 | M      | 3000   |
| 7 | mary   |   18 | N      | 6000   |
| 8 | king   |   28 | M      | 4600   |
| 9 | hellen |   30 | M      | 3000   |
+----+--------+------+--------+--------+
7 rows in set (0.00 sec)

mysql> update boss set Name= ‘jini‘ where GongZI = ‘3000‘; 更新数据
Query OK, 2 rows affected (0.00 sec)
Rows matched: 2 Changed: 2 Warnings: 0

mysql> select * from boss;
+----+------+------+--------+--------+
| ID | Name | Age | Gender | GongZI |
+----+------+------+--------+--------+
| 2 | mara |   35 | M      | 3600   |
| 3 | jini |   77 | N      | 5800   |
| 5 | boy |   35 | M      | 2600   |
| 6 | jini |   77 | M      | 3000   |
| 7 | mary |   18 | N      | 6000   |
| 8 | king |   28 | M      | 4600   |
| 9 | jini |   30 | M      | 3000   |
+----+------+------+--------+--------+
7 rows in set (0.00 sec)

mysql> update boss set Name= ‘jimi‘ where GongZI = ‘5800‘; 更新数据
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0

mysql> select * from boss;
+----+------+------+--------+--------+
| ID | Name | Age | Gender | GongZI |
+----+------+------+--------+--------+
| 2 | mara |   35 | M      | 3600   |
| 3 | jimi |   77 | N      | 5800   |
| 5 | boy |   35 | M      | 2600   |
| 6 | jini |   77 | M      | 3000   |
| 7 | mary |   18 | N      | 6000   |
| 8 | king |   28 | M      | 4600   |
| 9 | jini |   30 | M      | 3000   |
+----+------+------+--------+--------+
7 rows in set (0.00 sec)

mysql> select * from boss where GongZI between 2000 and 5000; 查询工资介于2000-5000的人
+----+------+------+--------+--------+
| ID | Name | Age | Gender | GongZI |
+----+------+------+--------+--------+
| 2 | mara |   35 | M      | 3600   |
| 5 | boy |   35 | M      | 2600   |
| 6 | jini |   77 | M      | 3000   |
| 8 | king |   28 | M      | 4600   |
| 9 | jini |   30 | M      | 3000   |
+----+------+------+--------+--------+
5 rows in set (0.00 sec)

mysql> select * from boss where Name like ‘%j%‘; like 比较消耗资源，尽量少使用
+----+------+------+--------+--------+
| ID | Name | Age | Gender | GongZI |
+----+------+------+--------+--------+
| 3 | jimi |   77 | N      | 5800   |
| 6 | jini |   77 | M      | 3000   |
| 9 | jini |   30 | M      | 3000   |
+----+------+------+--------+--------+
3 rows in set (0.01 sec)

mysql> select * from boss where Name rlike ‘^j.*$‘; 模糊查找基于正则
+----+------+------+--------+--------+
| ID | Name | Age | Gender | GongZI |
+----+------+------+--------+--------+
| 3 | jimi |   77 | N      | 5800   |
| 6 | jini |   77 | M      | 3000   |
| 9 | jini |   30 | M      | 3000   |
+----+------+------+--------+--------+
3 rows in set (0.00 sec)

mysql> show engines;    查看存储引擎
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| Engine     | Support | Comment                                                    | Transactions | XA   | Savepoints |
+------------+---------+------------------------------------------------------------+--------------+------+------------+
| MRG_MYISAM | YES     | Collection of identical MyISAM tables                      | NO           | NO   | NO         |
| CSV        | YES     | CSV storage engine                                         | NO           | NO   | NO         |
| MyISAM     | DEFAULT | Default engine as of MySQL 3.23 with great performance     | NO           | NO   | NO         |
| InnoDB     | YES     | Supports transactions, row-level locking, and foreign keys | YES          | YES | YES        |
| MEMORY     | YES     | Hash based, stored in memory, useful for temporary tables | NO           | NO   | NO   &

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