若删除关系R中的全部元组,下列哪一个语句是正确的?
A.DROP TABLE R;
B.DELETE FROM R;
C.DROP * FROM TABLE R;
D.DELETE * FROM R;
- · 有6位网友选择 A,占比60%
- · 有2位网友选择 B,占比20%
- · 有2位网友选择 C,占比20%
A.DROP TABLE R;
B.DELETE FROM R;
C.DROP * FROM TABLE R;
D.DELETE * FROM R;
A、SELECT Sno FROM SC WHERE Grade >= 0;
B、SELECT Sno FROM SC WHERE Grade != 0;
C、SELECT Sno FROM SC WHERE Grade NOT IS NULL;
D、SELECT Sno FROM SC WHERE Grade IS NOT NULL;
A、UPDATE Student.Sage SET Sage = Sage + 1;
B、UPDATE Student.* FROM Student SET Sage = Sage + 1;
C、UPDATE Student SET Sage = Sage + 1;
D、UPDATE Student.Sage SET Sage = 1+Sage;
A、(S,J )
B、(S,T )
C、(S,T,J )
D、(T,J )
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