摘要：USE myemployees;/*in :判断某字段的值是否属于in列表中个某一项特点：in方法更简单in列表的值类型必须一致或兼容*/SELECT last_name,job_id FROM employees WHERE job_id IN ('IT_PROF', 'AD_VP', 'AD_P 阅读全文

摘要：CREATE TABLE job_grades(grade_level VARCHAR(3),lowest_sal INT,highest_sal INT); INSERT INTO job_grades VALUE ('A', 1000, 2999);INSERT INTO job_grades 阅读全文

摘要：DROP DATABASE IF EXISTS student;CREATE DATABASE student;USE student; CREATE TABLE student( studentno VARCHAR(10) NOT NULL PRIMARY KEY, studentname VAR 阅读全文