A.m:n B.1:m C.m:1 D.1:1
A.數(shù)據(jù)參照完整性 B.數(shù)據(jù)控制 C.數(shù)據(jù)管 D.數(shù)據(jù)恢復(fù)
A.數(shù)據(jù)結(jié)構(gòu)化 B.數(shù)據(jù)獨(dú)立性強(qiáng) C.數(shù)據(jù)共享性高 D.數(shù)據(jù)面向應(yīng)用程序