interview questions select case when null = null then 'Yup' else 'Nope' end as Result;

Answer 1

nope

Answer 2

correct

Answer 3

nope

Answer 4

nope

Answer 5

result = nope as you need to use 'is' operator with null values in place of '=' to get yup

Answer 6

NULL means unknown. Hence two unknown NULLs can't be same/equal. The above solution provided by Saurabh Joshi is correct. I tried it myself and it works. :). Thanks.

select case when null is null then 'yup' else 'nope' end as result;

Answer 7

The null has a memory reference. So, one null value cannot be equal to another null value.

See the below result:

select
case when null=null
then 'Yes'
else 'No'
end
as Result
from dual;
================================================

Result=No