编辑代码

create database myhome;
CREATE DATABASE test;
use test;
CREATE TABLE student (
	id int,
	name varchar(255),
	address varchar(255),
	city varchar(25)
);

INSERT INTO student VALUES (1, '刘一', '郑十家隔壁', '河南');
INSERT INTO student VALUES (2, '陈二',  '李四家隔壁', '安徽');
INSERT INTO student VALUES (3, '张三',  '白娘子家隔壁', '杭州');
INSERT INTO student VALUES (4, '李四',  '许仙家隔壁', '杭州');
INSERT INTO student VALUES (5, '王五',  '李四家隔壁', '杭州');
INSERT INTO student VALUES (6, '赵六',  '赵六家隔壁', '杭州');
INSERT INTO student VALUES (7, '孙七',  '张三家隔壁', '杭州');
INSERT INTO student VALUES (8, '周八',  '雷峰塔附近', '杭州');
INSERT INTO student VALUES (9, '吴九',  '孙七家隔壁', '杭州');
INSERT INTO student VALUES (10, '郑十',  '周八家隔壁', '杭州');
 
 insert into student (id, name, address, city)
    VALUES (
     5, '五格', '许仙家楼下', '横店'
     );

update student set address = '白蛇家隔壁'where id = 3;

select address from student where id = 5;
update student set city = '西湖' where id = 3;

SELECT * FROM student;
SELECT city, COUNT(*) AS student_count
FROM student
GROUP BY city;