MySQL

Posted 2020-12-13 zwnsyw

-- 创建数据库
create database python_test charset=utf8;

-- 查看数据库
show databases;

-- 使用数据库
use python_test;

-- 显示当前使用那个数据库
select database();

-- 创建一个数据表  存0 1时使用bit 就行  bit(2)可以存4种 tinyint = bit(8)  2^8 = 256
create table studuent(
    id int unsigned primary key auto_increment not null,
    name varchar(20) default ‘‘,
    age tinyint unsigned default 0,
    height decimal (5,2),
    gender enum(‘男‘, ‘女‘, ‘中性‘, ‘保密‘) default ‘保密‘,
    cls_id int unsigned default 0,
    is_delete bit default 0
);

create table class(
    id int unsigned auto_increment primary key not null,
    name varchar(30) not null
);

-- 向表中插入数据
insert into studuent values
    (0,‘小明‘,18,168.00,2,1,0),
    (0,‘小黄‘,17,175.00,1,2,0),
    (0,‘小红‘,14,177.00,2,3,0),
    (0,‘小汉‘,11,180.00,3,4,0),
    (0,‘小八‘,12,187.00,3,5,0),
    (0,‘小九‘,13,182.00,4,6,0),
    (0,‘小十‘,18,188.00,3,7,0),
    (0,‘小之‘,17,186.00,2,8,0),
    (0,‘小一‘,10,188.00,2,9,0),
    (0,‘小二‘,15,182.00,3,9,0),
    (0,‘小三‘,18,184.00,2,6,0),
    (0,‘小四‘,19,185.00,4,4,0),
    (0,‘小五‘,13,190.00,2,3,0),
    (0,‘小六‘,14,189.00,2,4,0),
    (0,‘小七‘,15,178.00,2,5,0),
    (0,‘十一‘,15,167.00,1,7,0),
    (0,‘十二‘,18,176.00,1,2,0);

insert into class values
    (0, "python01期"),
    (0, "python02期"),
    (0, "python04期");

show tables ;

desc class;

select * from studuent;