题型:问答题 简答题 — We’ll study in different schools next term. Enjoy your time in the new school!— ________A.I’ll take your advice.B.The same to you.C.Congratulations!D.Me too. 查看答案
题型:问答题 简答题 设学生选课关系模式为SC(Sno,Cno,Grade),其中Sno为学号,Cno为课程号,Grade为成绩,SOL杳询语句如下: 与该查询等价的元组演算表达式为t| (13) (SC(u)∧SC(v)∧ (14) ∧t[1]=u[1])。 查看答案