mysql基本命令

# 本地
1、启动 mysql-->进入D:mysql-8.0.19-winx64in目录下
D:mysql-8.0.19-winx64in>net start mysql    # 如果启动报错，管理员身份启动cmd

2、登录 mysql
D:mysql-8.0.19-winx64in>:mysql -u root -p
Enter password:********
D:mysql-8.0.19-winx64in>:mysql -h localhost -u root -p

3、退出 mysql输入界面
mysql>exit;

4、关闭 mysql
D:mysql-8.0.19-winx64in>:net stop mysql

5、显示所有数据库
mysql>SHOW DATABASES:

6、创建数据库
mysql>CREATE DATABASE five;    创建数据库
mysql>CREATE DATABASE dbtest;
    6.1、删除数据库
mysql>drop database dbtest;    删除数据库(全部删除，不可撤销)

7、查看正在使用的数据库
mysql>select database();

8、使用指定数据库
mysql>use five;    使用指定数据库
mysql>show tables;    查看指定数据库的所有表
mysql>desc user;    查看表的信息
mysql>show create table user g    查看创建表的sql，命令最后不用加";"
mysql>show fields from user;    查看表格所有信息

9、创建 table
mysql>create table user(
    id int primary key,
    name varchar(50),
    age int,
    address varchar(100)
    );
9.1、创建自动增加编号
mysql> create table tbtest(
    id int not null primary key auto_increment,
    name varchar(20),
    city varchar(20),
    hobby varchar(20)
    );
9.2、修改表格
mysql>alter table user modify id int auto_increment primary key;    修改id为自增
mysql>alter table user add (column) data date not null;    添加列
mysql>alter table user drop data;    删除列
mysql>alter table user rename userinfo;    修改表名

10、删除 table或者数据
mysql>drop table user;    (表结构和数据全部删除，不可撤销)
mysql>truncate table user;    (只能操作表，将表中数据全部删除)
mysql>delete from user;    (删除整张表中数据)
mysql>delete from user where name='sunshine';;    （删除符合条件的数据)

11、备份数据库
mysql>INSERT INTO newuser SELECT * FROM user;    备份数据库

12、查看表中信息
mysql>SELECT * FROM user;    查看表格信息

11、向表中中插入数据
mysql> insert into user(name,age,address) values ('xxxx',20,'chongqing');
mysql>insert into user(name,age,address) values ('xxxxx',20,'chongqing');

# 选择性查找
mysql>select * from user;
mysql>select * from user where name='sunshine1';

# 反向查找
mysql>select * from user where age != 18;

# 附条件删除 row(行)
mysql>DELETE FROM tbCustomerInfo_back_up WHERE custInfoPhone = '10000000000';
mysql>DELETE FROM tbCustomerInfo_back_up WHERE custInfoFirstName = 'William2' ADN custInfoLastName = 'Jiamin2';

# 贴 index 的方法
mysql>SHOW FIELDS FROM tbCustomerIDInfo;
mysql>create index indexcustidinfo on tbcustomeridinfo (custid);    贴标签
mysql>create index indexcustnameinfo on tbcustomeridinfo (custinfofirstname,custinfolastname);

# 自动增加编号
mysql>show databases;
mysql>use dbcustomerinfo;
mysql>show tables;
mysql>create table tbcustomerid_auto(id int primary key auto_increment,name varchar(20));
mysql>show fields from tbcustomerid_auto;
mysql>insert into tbcustomerid_auto(name) values ('William');
mysql>insert into tbcustomerid_auto(name) values ('Tony');
mysql> insert into tbcustomerid_auto(name) values ('Jery');
mysql>insert into tbcustomerid_auto(name) values ('Mary');
mysql>select * from tbcustomerid_auto;

# 调整开始的数
mysql>alter table tbcustomerid_auto auto_increment=10000;
mysql>insert into tbcustomerid_auto (name) values ('I_am_soooo_IMP1');
mysql>insert into tbcustomerid_auto (name) values ('I_am_soooo_IMP2');

# sql 自带 count 函数
mysql>select count(*) from tbcustomerinfo;
mysql>select count(distinct custinfofirstname) from tbcustomerinfo;    # distinct 去重
mysql>select count(custinfolastname) from tbcustomerinfo where custinfolastname = 'lexueoude';

# 创建员工薪酬表
mysql> create table tbstaffsalary(staffid int primary key auto_increment,name,
         name varchar(30),
         staffage int,
         staffsalary int);
mysql>show fields from tbstaffsalary;
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('William',18,1);
mysql>select * form tbstaffsalary;
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Wangcongcong',25,900000000);
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Normal People',27,8000);
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Normal People2',24,9000);
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Normal People3',23,5000);
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Normal People4',30,10000);
mysql>insert into tbstaffsalary(name,staffage,staffsalary) values('Normal People5',45,18000);

# 员工薪酬表运算
mysql>select count(*) from tbstaffsalary;
mysql>select avg(staffage) from tbstaffsalary;
mysql>select count(*),avg(staffage) from tbstaffsalary;
mysql>select count(*),avg(staffage),avg(staffsalary) from tbstaffsalary;

# like 模糊查找
mysql>select count(*),sum(staffsalary),avg(staffsalary) from tbstaffsalary where name like 'normal%';
mysql>select count(*),sum(staffsalary),avg(staffsalary) from tbstaffsalary where name like '%mal%';
mysql>select count(*),sum(staffsalary),avg(staffsalary) from tbstaffsalary where name like '%g';

# 创建 view
mysql>create view williamview as select count(*),avg(staffsalary),sum(staffsalary) from tbstaffsalary where staffsalary > 1;
mysql>select * from williamview;
mysql>show tables;
mysql>create view williamview2 as select count(*),avg(staffsalary),sum(staffsalary) from tbstaffsalary where staffsalary < 50000;
mysql>select * from williamview2;

# join 的准备工作移动编号
mysql>alter table tbcustomerinfo change custinfoid custinfoid int auto_increment not null after custinfoaddr2;    # custinfoid 跟在custinfoaddr2 后面
mysql>alter table tbcustomerinfo change custinfoid custinfoid int auto_increment not null first;    # 将 custinfoid 放在第一位

# join 的准备工作订单信息
mysql>create table tbcustomerorder (orderid int primary key auto_increment,
         custid int,
         orderdate date);
mysql>show tables;
mysql>show fields from tbcustomerorder;
mysql>insert into tbcustomerorder (custid,orderdate) values ('1',20191111);
mysql>insert into tbcustomerorder (custid,orderdate) values ('3',20201111);
mysql>insert into tbcustomerorder (custid,orderdate) values ('2',20211111);
mysql>insert into tbcustomerorder (custid,orderdate) values ('4',20251111);

# innerjoin 满足老板的要求（一一对应）
mysql>select tbcustomerorder.orderid,tbcustomerinfo.custinfolastname,tbcustomerorder.orderdate from tbcustomerorder inner join tbcustomerinfo on tbcustomerorder.custid=tbcustomerinfo.custinfoid;

# leftjoin 满足老板要求 （以左边的表格为主，右边跟其一一对应）
mysql>insert into tbcustomerinfo (custinfolastname) values ('Bill');
mysql>select * from tbcustomerinfo;
mysql>select tbcustomerorder.orderid, tbcustomerinfo.custinfolastname, tbcustomerorder.orderdate from tbcustomerinfo left join tbcustomerorder on tbcustomerinfo.custinfoid=tbcustomerorder.custid order by tbcustomerinfo.custinfolastname;

# rightjoin 满足老板要求（以右边的表格为主，左边跟其一一对应）
mysql>select tbcustomerorder.orderid, tbcustomerinfo.custinfolastname, tbcustomerorder.orderdate from tbcustomerinfo right join tbcustomerorder on tbcustomerinfo.custinfoid=tbcustomerorder.custid order by tbcustomerinfo.custinfolastname;

# fulljoin 满足老板要求 (报错)
mysql>select tbcustomerorder.orderid, tbcustomerinfo.custinfolastname, tbcustomerorder.orderdate from tbcustomerinfo full outter join tbcustomerorder on tbcustomerinfo.custinfoid=tbcustomerorder.custid order by tbcustomerinfo.custinfolastname;

# union 准备工作
mysql>insert into tbcustomerorder(custid, orderdate) values ('5',20201111);

# union 介绍
mysql>select * from tbcustomerorder union select custinfoid, custinfofirstname,custinfolastname from tbcustomerinfo;

# union 实现 fulljoin
mysql>select tbcustomerinfo.custinfolastname, tbcustomerorder.custid from tbcustomerinfo left join tbcustomerorder on tbcustomerinfo.custinfoid=tbcustomerorder.custid union
   select tbcustomerinfo.custinfolastname, tbcustomerorder.custid from tbcustomerinfo right join tbcustomerorder on tbcustomerorder.custid=tbcustomerinfo.custinfoid;

# order 实现排序
mysql>select * from tbcustomerinfo order by custinfolastname desc;    # 降序排列
mysql>select * from tbcustomerinfo order by custinfolastname asc;    # 升序排列
mysql>select * from tbcustomerinfo order by custinfolastname desc limit 10;    # 限制显示前10行的

# 找到最大值和最小值
mysql>select max(custinfoid) from tbcustomerinfo;
mysql>select custinfoid, custinfolastname from tbcustomerinfo where custinfoid =(select max(custinfoid) from tbcustomerinfo);

# select 大小写
mysql>select ucase(custinfofirstname) , lcase(custinfolastname) from tbcustomerinfo;