2. 计算机
  3. Let R and S be the relation respectively: Relation R: A B C Relation S: B C D 1 2 3 2 3 4 6 7 8 2 3 5 The number of tuplesthat t

Let R and S be the relation respectively: Relation R: A B C Relation S: B C D 1 2 3 2 3 4 6 7 8 2 3 5 The number of tuplesthat t

admin2005-05-04  65
问题 Let R and S be the relation respectively: Relation R: A B C Relation S: B C D 1 2 3 2 3 4 6 7 8 2 3 5 The number of tuplesthat the result of the expression R ∞ S (Here is the natural join of relations R and S) is
选项 A、3
B、4
C、6
D、9
答案B
解析
转载请注明原文地址:https://jikaoti.com/ti/dbE7FFFM
0

笔试

原NCRE全国计算机四级

NCRE全国计算机四级

相关试题推荐
随机试题
最新回复(0)