1 votes 1 votes Databases sql + – bahirNaik asked Dec 6, 2015 bahirNaik 451 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 1 votes 1 votes The answer should be C In Sql, duplicate rows are allowed, if no primary key is set. also, all the null values are considered as null and we cannot diffrentiate between the different null values obtained. learncp answered Dec 9, 2015 selected Jan 28, 2016 by Arjun learncp comment Share Follow See all 0 reply Please log in or register to add a comment.
2 votes 2 votes i think a should be the answer. because . 1- sql does not treat every null same . sql treat null as unknown and we cannot compare two Null value by a equality and the group by command also count every null as unique group, 2- the asnwer may be yes , u can create a table with no primary key which will be useless because join operation will not be sucessful and that table will not be in 1nf. Tendua answered Dec 6, 2015 Tendua comment Share Follow See all 0 reply Please log in or register to add a comment.
1 votes 1 votes Ans is C. Multisets are allowed. Refer : http://waelchatila.com/2005/05/18/1116485743467.html Mojo-Jojo answered Dec 9, 2015 Mojo-Jojo comment Share Follow See all 0 reply Please log in or register to add a comment.