标签：.sql utf8 inner specified 根据 行操作 进入 names 作文件
1.mysql安装
windows
-可执行文件
-压缩包
-放置任意目录
-初始化
1.1 管理员命令进入mysql bin目录
-初始化
mysqld --initialize
-启动服务端
D:\mysql\mysql-5.6.41-winx64\bin\mysqld
-启动客户端
D:\mysql\mysql-5.6.41-winx64\bin\mysql -u root -p 密码为空
C:\Users\lenovo>D:\mysql\mysql-5.6.41-winx64\bin\mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.41 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.00 sec)
mysql> create database db1;
Query OK, 1 row affected (0.01 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| mysql |
| performance_schema |
| test |
+--------------------+
5 rows in set (0.00 sec)
2 添加环境变量
D:\mysql\mysql-5.6.41-winx64\bin
关闭终端关闭进程
2.1 启动服务端
mysqld
2.2 启动客户端
mysql -u root -p
3 windows服务
以管理员身份运行cmd命令
D:\mysql\mysql-5.6.41-winx64\bin\mysqld --install
D:\mysql\mysql-5.6.41-winx64\bin\mysqld --remove
"D:\mysql\mysql-5.6.41-winx64\bin\mysqld" --install
以管理员身份运行cmd命令启动mysql服务
启动：net start mysql
停止：net stop mysql
以用户运行cmd命令进入客户端
mysql -u root -p
密码修改：set password=password(‘123‘)
4 关于连接
文件夹-数据库
文件-表
数据行-行
用户：root
查看用户信息：
show databases;
use mysql;
show tables;
select user from user;
创建用户：
create user ‘test‘@‘ip‘ identified by ‘123‘;
create user ‘test‘@‘192.168.%‘ identified by ‘123‘;
create user ‘test‘@‘%‘ identified by ‘test‘;
授权：
grant 权限 to wzh;
grant select,insert,update on db1.* to ‘test‘@‘%‘;
grant all privileges on db1.* to ‘test‘@‘%‘; --所有权限
sql语句
操作文件夹
create database db2 default charset=utf8;
show databases;
drop database db2;
操作文件
show tables;
create table t1(id int,name char(10)) default charset=utf8;
create table t1(id int,name char(10)) engine=innodb default charset=utf8; --加入引擎
#innodb支持回滚操作 支持事务操作
crate table t(
列名 类型 null,
列名 类型 not null,
列名 类型 not null default 1, --默认值
列名 类型 not null auto_increment primary key --自增 是自增必须是一个key 一个表只能一个自增列
)engine=innodb default charset=utf8
数据类型：
数值
tigyint
int
bigint
float
double 不太精准的小数
decimal 精准的 底层是按字符串存储
字符串
char(10) 速度快 定长的数据类型放前面
varchar(10) 节省空间 速度没有char快
-后面都需要加长度
-最高255字符
text 65535
longtext
上传文件：
存储在硬盘，数据库中存路径
时间类型
date
time
year
datetime
timestamp
枚举类型 enum
集合类型 set
操作文件中内容
select * from t1;
插入数据，插入中文时会乱码
insert into t1(id,name) values(1,‘A‘);
insert into t1(id,name) values(1,‘测试‘);
解决中文乱码问题：
在创建时设置字符集 default charset utf8
清空表内容：
delete from t1;
truncate table t1;
删除表：
drop table t1;
5 增删改查
insert
delete
update
select
6 外键
emp表 dept表
create table emp(
id int auto_increment primary key,
name varchar(50),
dept_id int,
constraint fk_emp_dept foreign key(dept_id) references dept(id)
)engine=innodb default charset=utf8;
create table dept(
id int auto_increment primary key,
dname varchar(50)
)engine=innodb default charset=utf8;
mysql> create table dept( -> id int auto_increment primary key, -> dname varchar(50) -> )engine=innodb default charset=utf8; Query OK, 0 rows affected (0.23 sec) mysql> create table emp( -> id int auto_increment primary key, -> name varchar(50), -> dept_id int, -> constraint fk_emp_dept foreign key(dept_id) references dept(id) -> )engine=innodb default charset=utf8; Query OK, 0 rows affected (0.27 sec) mysql> insert into dept(dname) values(‘sales‘); Query OK, 1 row affected (2.05 sec) mysql> insert into dept(dname) values(‘analysis‘); Query OK, 1 row affected (0.41 sec) mysql> select * from dept; +----+----------+ | id | dname | +----+----------+ | 1 | sales | | 2 | analysis | +----+----------+ 2 rows in set (0.00 sec) mysql> insert into emp(name,dept_id) values(‘A‘,1); Query OK, 1 row affected (2.06 sec) mysql> select * from emp; +----+------+---------+ | id | name | dept_id | +----+------+---------+ | 1 | A | 1 | +----+------+---------+ 1 row in set (0.00 sec) mysql> insert into emp(name,dept_id) values(‘A‘,3); ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`db2`.`emp`, CONSTRAINT `fk_emp_dept` FOREIGN KEY (`dept_id`) REFERENCES `dept` (`id`))
查看表创建
show create table emp \G;
自增设置
mysql> create table t2(id int auto_increment primary key,num int)engine=innodb default charset=utf8; Query OK, 0 rows affected (2.30 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 1 row in set (0.00 sec) ERROR: No query specified mysql> insert into t2(num) values(1); Query OK, 1 row affected (0.08 sec) mysql> insert into t2(num) values(2); Query OK, 1 row affected (0.07 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) ERROR: No query specified mysql> insert into t2(num) values(3); Query OK, 1 row affected (2.06 sec) mysql> insert into t2(num) values(4); Query OK, 1 row affected (0.06 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) ERROR: No query specified mysql> delete from t2 where id=3; Query OK, 1 row affected (0.70 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) ERROR: No query specified mysql> insert into t2(num) values(5); Query OK, 1 row affected (0.12 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) mysql> alter table t2 AUTO_INCREMENT=10; Query OK, 0 rows affected (2.06 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8 1 row in set (0.00 sec) mysql> insert into t2(num) values(6); Query OK, 1 row affected (2.05 sec) mysql> show create table t2 \G; *************************** 1. row *************************** Table: t2 Create Table: CREATE TABLE `t2` ( `id` int(11) NOT NULL AUTO_INCREMENT, `num` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8 1 row in set (0.00 sec)
自增步长 基于会话级别步长
--查看会话步长 mysql> show session variables like ‘auto_inc%‘; +--------------------------+-------+ | Variable_name | Value | +--------------------------+-------+ | auto_increment_increment | 1 | | auto_increment_offset | 1 | +--------------------------+-------+
--设置会话步长 mysql> set session auto_increment_increment=2; Query OK, 0 rows affected (0.00 sec) mysql> select * from emp; +----+------+---------+ | id | name | dept_id | +----+------+---------+ | 1 | A | 1 | +----+------+---------+ 1 row in set (0.00 sec) mysql> insert into emp(name,dept_id) values(‘B‘,1); Query OK, 1 row affected (2.09 sec) mysql> select * from emp; +----+------+---------+ | id | name | dept_id | +----+------+---------+ | 1 | A | 1 | | 3 | B | 1 | +----+------+---------+ 2 rows in set (0.00 sec) mysql> show session variables like ‘auto_inc%‘; +--------------------------+-------+ | Variable_name | Value | +--------------------------+-------+ | auto_increment_increment | 2 | | auto_increment_offset | 1 | +--------------------------+-------+
全局步长设置
set global auto_increment_increment=20;
会话和全局步长
--会话 show session variables like ‘auto_inc%‘; --查看 set session auto_increment_increment=2; --步长 set session auto_increment_offset=10; --起始值 --全局 show global variables like ‘auto_inc%‘; set global auto_increment_increment=2; set global auto_increment_offset=10;
===========================分割============================
1.唯一约束
create table t1(
id int,
num int,
d_id int,
unique uq1(num)
unique uq2(num,d_id) --联合唯一
)
ps:唯一约束不能重复（可以为空）
加速查找
2 外键的变种
外键+唯一 ===> 一对一
create table userinfo1( id int auto_increment primary key, name char(10), gender char(10), email varchar(64) )engine=innodb default charset=utf8; create table admin( id int not null auto_increment primary key, username varchar(64) not null, password VARCHAR(64) not null, user_id int not null, unique uq_u1 (user_id), CONSTRAINT fk_admin_u1 FOREIGN key (user_id) REFERENCES userinfo1(id) )engine=innodb default charset=utf8;
多对多 -- 多张表 双向一对多 在第三张表中有多个外键，根据需求可以将这多个外键联合唯一
create table userinfo2( id int auto_increment primary key, name char(10), gender char(10), email varchar(64) )engine=innodb default charset=utf8; create table host( id int auto_increment primary key, hostname char(64) )engine=innodb default charset=utf8; create table user2host( id int auto_increment primary key, userid int not null, hostid int not null, unique uq_user_host (userid,hostid), CONSTRAINT fk_u2h_user FOREIGN key (userid) REFERENCES userinfo2(id), CONSTRAINT fk_u2h_host FOREIGN key (hostid) REFERENCES host(id) )engine=innodb default charset=utf8;
sql语句数据行操作
--增 create table tb12( id int auto_increment primary key, name varchar(32), age int )engine=innodb default charset=utf8; insert into tb12(name,age) values(‘A‘,22); --插入单条 insert into tb12(name,age) values(‘A‘,22),(‘B‘,33); --插入多条 create table tb13( id int auto_increment primary key, name varchar(32), age int )engine=innodb default charset=utf8; insert into tb13(name,age) select name,age from tb12; -- 从另一张表插入新的表 --删 delete from tb12 where id = 1; -- 可以用 < 、>、 !=、 not 、not in -- 改 update tb12 set name=‘C‘,age=33 where id = 1 and name = ‘A‘; -- 查 select id,name,age from tb12 where id = 1; select name,age from tb12 where age like ‘3%‘; -- 通配符 select name,age from tb12 where age like ‘3_‘; select name,age from tb12 limit 1,2; -- 分页 select name,age from tb12 limit 3 offset 1; -- 从第1行读（不含1），读取3行 select * from tb12 order by id desc -- 排序 asc升序 select * from tb12 order by id desc limit 10; -- 取后10条数据 select age,count(id) from tb12 group by age; -- 分组 select age,count(id) from tb12 group by age having count(id) > 1; -- 分组后的数据进行筛选 --连表操作 select t12.name,t13.age from t12 left join t13 on t12.id = t13.id -- 左外连接 左表为基表匹配右表，匹配不上的空值补充 --right join 右表全部显示 --inner join 匹配上的数据 --outer full join 显示全部
转储sql文件
-- 在当前目录下产生db1.sql文件 数据表结构+数据 mysqldump -u root db1 > db1.sql -p -- 加参数 -d 数据库表结构 mysqldump -u root -d db1 > db1.sql -p -- 导入现有数据库 < mysqldump -u root -d db1 < db1.sql -p
标签：.sql utf8 inner specified 根据 行操作 进入 names 作文件
原文地址：https://www.cnblogs.com/wangzihong/p/9822518.html
