SET NAMES UTF8; DROP DATABASE IF EXISTS md; CREATE DATABASE md CHARSET=UTF8; USE md; CREATE TABLE stu( sid INT PRIMARY KEY AUTO_INCREMENT, gender VARCHAR(1), class VARCHAR(3) ); CREATE TABLE phoneType( ptId INT PRIMARY KEY AUTO_INCREMENT, ptName VARCHAR(16) ); CREATE TABLE phone( pid INT PRIMARY KEY AUTO_INCREMENT, pname VARCHAR(32), ptId INT ); CREATE TABLE sale( id INT PRIMARY KEY AUTO_INCREMENT, pid INT, sid INT, price DECIMAL(7,2), total INT ); INSERT INTO stu VALUES(NULL,'M','171'); INSERT INTO stu VALUES(NULL,'F','172'); INSERT INTO stu VALUES(NULL,'F','173'); INSERT INTO stu VALUES(NULL,'M','171'); INSERT INTO stu VALUES(NULL,'M','172'); INSERT INTO stu VALUES(NULL,'M','171'); INSERT INTO phoneType VALUES(NULL,'iPhone'); INSERT INTO phoneType VALUES(NULL,'Xiaomi'); INSERT INTO phoneType VALUES(NULL,'HUAWEI'); INSERT INTO phoneType VALUES(NULL,'OPPO'); INSERT INTO phone VALUES(NULL,'iPhone 11',1); INSERT INTO phone VALUES(NULL,'iPhone X',1); INSERT INTO phone VALUES(NULL,'HUAWEI Mate 30',2); INSERT INTO phone VALUES(NULL,'HUAWEI Pro 30',2); INSERT INTO phone VALUES(NULL,'Xiaomi 9',3); INSERT INTO phone VALUES(NULL,'Xiaomi 8',3); INSERT INTO phone VALUES(NULL,'OPPO K5',4); INSERT INTO phone VALUES(NULL,'OPPO Reno 2',4); INSERT INTO sale VALUES(NULL,1,1,12399.00,1); INSERT INTO sale VALUES(NULL,2,2,9999.00,2); INSERT INTO sale VALUES(NULL,3,3,12000.00,3); INSERT INTO sale VALUES(NULL,4,4,14000.00,3); INSERT INTO sale VALUES(NULL,5,5,3999.00,6); INSERT INTO sale VALUES(NULL,6,6,2999.00,5); INSERT INTO sale VALUES(NULL,7,6,4999.00,3); INSERT INTO sale VALUES(NULL,8,1,5999.00,4); INSERT INTO sale VALUES(NULL,2,1,9999.00,1); INSERT INTO sale VALUES(NULL,2,3,9999.00,1); INSERT INTO sale VALUES(NULL,5,3,3999.00,3); INSERT INTO sale VALUES(NULL,5,3,3999.00,4); INSERT INTO sale VALUES(NULL,5,5,3999.00,6); INSERT INTO sale VALUES(NULL,6,4,2999.00,8); INSERT INTO sale VALUES(NULL,8,1,5999.00,2); INSERT INTO sale VALUES(NULL,1,3,12399.00,1);