Can we use more than one null value for unique key?
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Answer Posted / arika
We can insert duplicate nul values in palce of using unique
key constrint.Because all nulls are not equal.
ex:-
select * from emp where comm=null;
explenation;
here equal operator not support null value because
all nulls are not equal
ex:-
select * from emp where comm is null;
explenation:
'is' operator suport null
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