如果关系模式R是BCNF范式,那么下列说法不正确的是( )。A.R必是3NF B.R 发布时间:2017-05-25 06:07 │ 来源:www.tikuol.com 题型:单项选择题 问题: 如果关系模式R是BCNF范式,那么下列说法不正确的是( )。A.R必是3NFB.R必是1NFC.R必是2NFD.R必是4NF
题型:单项选择题 Quite a few of the swamps have become due to the industry development. [ ]A. endangered B. polluted C. horrified D. terrified 查看答案