Select语句中的不明确的列名称

Question

此查询返回错误"ambiguous column name courses.scheduleNumber".我搜索了问题的解决方案,但是,一个常见的修复方法是使用表名限定所有列名,我已经完成了.

SELECT
  courses.scheduleNumber,
  courses.subject,
  courses.courseNumber,
  courses.sectionNumber,
  courses.credits,
  courses.title,
  courses.room,
  courses.days,
  rooms.building,
  rooms.room,
  courses.startTime,
  courses.endTime,
  courses.instructor
FROM courses
LEFT JOIN courseRooms 
  ON courses.scheduleNumber=courseRooms.scheduleNumber
LEFT JOIN courses 
  ON courseRooms.building=rooms.building AND courseRooms.room=rooms.room;

Answer 1

我认为你的意思是最终LEFT JOIN courses成为一个LEFT JOIN rooms？