題目是用子查詢查詢成績不及格的設(shè)計MySchool數(shù)據(jù)庫課程的學(xué)生學(xué)號，姓名select StudentNo,StudentName,GradeIdfrom Studentwhere GradeId=( select GradeID from Subject where SubjectName='設(shè)計MySchool數(shù)據(jù)庫' and SubjectID in( select SubjectID from Result where StudentResult<60? ))select StudentNo,StudentName,GradeIDfrom Studentwhere StudentNo in( select StudentNo from Result where ?StudentResult<60 and SubjectID =( select SubjectID from Subject where SubjectName='設(shè)計MySchool數(shù)據(jù)庫' ))為什么條件倒換一下答案就錯了，下面的一段代碼是對的