CREATE DATABASE test;
use test;
create table emp(
id int comment '编号',
workno varchar(10) comment '工号',
name varchar(10) comment '姓名',
gender char(1) comment '性别',
age tinyint unsigned comment '年龄',
idcard char(18) comment '身份证号',
workaddress varchar(50) comment '工作地址',
entrydate date comment '入职时间'
)comment '员工表';
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (1, '2008110001', '赵宝亮', '男', 33, '379181198802043044', '山东', '1998-02-01');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (2, '2008110002', '李发', '男', 23, '379181198828849201', ' 浙江', '2012-03-05');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (3, '2008110003', '张一山', '男', 17, '373297592384759876', '北京', '2021-02-01');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (4, '2008110004', '杨紫', '女', 19, '374974798989198957', '上海', '2009-01-01');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (5, '2008110005', '王俊凯', '男', 27, '349734576667885988', '北京', '2013-05-23');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (6, '2008110006', '李一一', '女', 37, '378787987896666553', '河南', '2022-01-01');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (7, '2008110007', '李艺彤', '女', 20, '374387658797827616', '山东', '2009-04-12');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (8, '2008110008', '张飞', '男', 19, '343888927651627748', '山东', '2003-09-11');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (9, '2008110009', '胡山', '男', 33, '337634778236755667', '浙江', '2006-05-17');
INSERT INTO emp (id, workno, name, gender, age, idcard, workaddress, entrydate) VALUES (10, '2008110010','王海波', '男', 48, '332767438766762553', '安徽', '2002-03-03');
select name,workno,age from emp;
select * from emp where age<20 ;
select*from emp where age<=20 and gender='女';
select avg(age) from emp;
select gender,avg(age) from emp group by gender;
select * from emp order by age asc;