数据库MySQL基础2

一、新建连接

可以使用Navicat新建数据库连接

创建连接后双击会有创建的数据库

可右键新建 

二、查询语句练习 这里之间点击新建查询写查询语句即可，重在熟练

 

 

三、MySQL查询语句作业小练习：

1、查询同时参与" 1 "课程和" 2 "课程考试的学生信息

SELECT DISTINCT s.*
FROM student s
JOIN score sc1 ON s.s_id = sc1.s_id AND sc1.c_id = '1'
JOIN score sc2 ON s.s_id = sc2.s_id AND sc2.c_id = '2';

2、查询在成绩表存在成绩的学生信息

SELECT DISTINCT s.*
FROM student s
JOIN score sc ON s.s_id = sc.s_id;

3、查询学过「李白」老师授课的同学的信息

SELECT DISTINCT s.*
FROM student s
JOIN score sc ON s.s_id = sc.s_id
JOIN course c ON sc.c_id = c.c_id
JOIN teacher t ON c.t_id = t.t_id
WHERE t.t_name = '李白';