本文介绍了在mysql中内联接3个表的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想从更多的表中选择内部连接的数据。
I want to select data from more tables with Inner join.
这是我的表。
Student (studentId, firstName, lastname) Exam (examId, name, date) Grade (gradeId, fk_studentId, fk_examId, grade)我要写一份声明,说明学生已经参加的考试,年级和日期。
I want to write a statement that shows which exam, grade and date alle the students have been to. Sorted after date.
这是我的陈述。它运行,但我想确保我做的正确。
This is my statement. It runs, but i want to make sure that i am doing it correctly.
SELECT student.firstname, student.lastname, exam.name, exam.date, grade.grade FROM grade INNER JOIN student ON student.studentId = grade.gradeId INNER JOIN exam ON exam.examId = grade.gradeId ORDER BY exam.date推荐答案
几乎正确..看看连接,你指的是错误的字段
Almost correctly.. Look at the joins, you are referring the wrong fields
SELECT student.firstname, student.lastname, exam.name, exam.date, grade.grade FROM grade INNER JOIN student ON student.studentId = grade.fk_studentId INNER JOIN exam ON exam.examId = grade.fk_examId ORDER BY exam.date更多推荐
在mysql中内联接3个表
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