451 views

3 Answers

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.
selected by
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.

Related questions

0 votes
0 votes
1 answer
1