多表查询sql语句（5表）

标签：语句   each   select   exists   王老师   sql   teacher   关联表   rom   

查询王老师的课程
SELECT t.name AS ‘老师‘,l.name AS ‘课程‘ FROM teacher t
LEFT JOIN teacher_lesson teal ON t.id = teal.teacher_id
LEFT JOIN lesson l ON l.id = teal.lesson_id WHERE t.name = ‘王老师‘

查询上了王老师或张老师课的学生

SELECT s.name AS ‘学生‘,l.name AS ‘课程‘,t.name AS ‘老师‘ FROM student s
LEFT JOIN student_lesson stul ON s.id = stul.student_id
LEFT JOIN lesson l ON l.id = stul.lesson_id
LEFT JOIN teacher_lesson teal ON teal.lesson_id = l.id
LEFT JOIN teacher t ON t.id = teal.teacher_id WHERE t.name = ‘王老师‘ OR t.name = ‘张老师‘

查询即上王老师又上张老师课的学生
SELECT * FROM student s WHERE EXISTS (
SELECT 1 FROM teacher_lesson tl JOIN teacher t ON tl.teacher_id = t.id
JOIN student_lesson sl ON sl.lesson_id = tl.lesson_id WHERE sl.student_id = s.id AND t.name = ‘王老师‘
) AND EXISTS (
SELECT 1 FROM teacher_lesson tl JOIN teacher t ON tl.teacher_id = t.id
JOIN student_lesson sl ON sl.lesson_id = tl.lesson_id WHERE sl.student_id = s.id AND t.name = ‘张老师‘
);

多表查询sql语句（5表）

标签：语句   each   select   exists   王老师   sql   teacher   关联表   rom   

原文地址：http://blog.51cto.com/13579083/2330696