CREATE View NPStuView AS SELECT Sno, Sname, Cno, Cname, Grade from Student, SC, Course WHERE Grade<60;
B.
CREATE View NPStuView (Sno, Sname, Cno, Cname, Grade) AS SELECT Student.Sno, Sname, Course.Cno, Cname, Grade from Student, SC, Course WHERE Student.Sno=SC.Sno and SC.Cno=Course.Cno and Grade<60;
C.
CREATE View NPStuView AS SELECT Student.Sno, Sname, Course.Cno, Cname, Grade from Student, SC, Course WHERE Student.Sno=SC.Sno and SC.Cno=Course.Cno and Grade<60;
D.
CREATE View NPStuView (Sno, Sname, Cno, Cname, Grade) SELECT Student.Sno, Sname, Course.Cno, Cname, Grade from Student, SC, Course WHERE Student.Sno=SC.Sno and SC.Cno=Course.Cno and Grade<60;
【简答题】已知: 反应① Fe (s) + CO 2 (g) FeO (s) + CO (g)的平衡常数为K 1 , 反应② Fe(s) + H 2 O (g) FeO (s) + H 2 (g)的平衡常数为K 2 , 不同温度下,K 1 、K 2 的值如下: (1)从上表可以推断:反应①是___________ (填“吸”、“放”)热反应 (2)现有反应③CO 2 (g) + H 2 (g) CO (g)...