MySQL query statement simple operation example

-- Create database create database python_test_1 charset=utf8;
--Use database use python_test_1;
--students table create table students(
  id int unsigned primary key auto_increment not null,
  name varchar(20) default '',
  age tinyint unsigned default 0,
  height decimal(5,2),
  gender enum('male', 'female', 'neutral', 'confidential') default 'confidential',
  cls_id int unsigned default 0,
  is_delete bit default 0
);
--classes table create table classes (
  id int unsigned auto_increment primary key not null,
  name varchar(30) not null
);

-- Insert data into the students table insert into students values
(0,'Xiaoming',18,180.00,2,1,0),
(0,'Xiao Yueyue',18,180.00,2,2,1),
(0,'Eddie Peng',29,185.00,1,1,0),
(0,'Andy Lau',59,175.00,1,2,1),
(0,'Huang Rong',38,160.00,2,1,0),
(0,'Fengjie',28,150.00,4,2,1),
(0,'王祖贤',18,172.00,2,1,1),
(0,'Jay Chou',36,NULL,1,1,0),
(0,'Cheng Kun',27,181.00,1,2,0),
(0,'Liu Yifei',25,166.00,2,2,0),
(0,'Venus',33,162.00,3,3,1),
(0,'Shizuka',12,180.00,2,4,0),
(0,'Guo Jing',12,170.00,1,4,0),
(0,'周杰',34,176.00,2,5,0);

-- Insert data into the classes table insert into classes values ​​(0, "python_01 period"), (0, "python_02 period");

select * from table name;

select * from students;

select column1, column2,... from tablename;

select name from students;

select id as serial number, name as name, gender as gender from students;

-- If it is a single table query, you can omit it to indicate select id, name, gender from students;
-- Table name. Field name select students.id, students.name, students.gender from students;
-- You can use as to give the table an alias select s.id,s.name,s.gender from students as s;

select distinct column1,... from tablename;

select distinct gender from students;