题目内容:
、有关系S(S#,SNAME,SAGE),C(C#,CNAME),SC(S#,C#,GRADE)。其中S#是学生号,SNAME是学生姓名,SAGE是学生年龄, C#是课程号,CNAME是课程名称。要查询选修“ACCESS”课的年龄不小于20的全体学生姓名的SQL语句是SELECT SNAME FROM S,C,SC WHERE子句。这里的WHERE子句的内容是( )。 A. S.S# = SC.S# and C# = SC.C# and SAGE>=20 and CNAME=‘ACCESS’
B. S.S# = SC.S# and C# = SC.C# and SAGE in>=20 and CNAME in ‘ACCESS’D
C. SAGE in>=20 and CNAME in ‘ACCESS’
D. SAGE>=20 and CNAME=’ ACCESS’
参考答案: