MySQL查詢語句簡單操作示例

-- 創(chuàng)建數(shù)據(jù)庫
create database python_test_1 charset=utf8;
-- 使用數(shù)據(jù)庫
use python_test_1;
-- students表
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('男','女','中性','保密') default '保密',
  cls_id int unsigned default 0,
  is_delete bit default 0
);
-- classes表
create table classes (
  id int unsigned auto_increment primary key not null,
  name varchar(30) not null
);

-- 向students表中插入數(shù)據(jù)
insert into students values
(0,'小明',18,180.00,2,1,0),
(0,'小月月',18,180.00,2,2,1),
(0,'彭于晏',29,185.00,1,1,0),
(0,'劉德華',59,175.00,1,2,1),
(0,'黃蓉',38,160.00,2,1,0),
(0,'鳳姐',28,150.00,4,2,1),
(0,'王祖賢',18,172.00,2,1,1),
(0,'周杰倫',36,NULL,1,1,0),
(0,'程坤',27,181.00,1,2,0),
(0,'劉亦菲',25,166.00,2,2,0),
(0,'金星',33,162.00,3,3,1),
(0,'靜香',12,180.00,2,4,0),
(0,'郭靖',12,170.00,1,4,0),
(0,'周杰',34,176.00,2,5,0);

-- 向classes表中插入數(shù)據(jù)
insert into classes values (0, "python_01期"), (0, "python_02期");

select * from 表名;

select * from students;

select 列1,列2,... from 表名;

select name from students;

select id as 序號, name as 名字, gender as 性別 from students;

-- 如果是單表查詢 可以省略表明
select id, name, gender from students;
-- 表名.字段名
select students.id,students.name,students.gender from students;
-- 可以通過 as 給表起別名 
select s.id,s.name,s.gender from students as s;

select distinct 列1,... from 表名;

select distinct gender from students;