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Question 
Can we have more than one NULL in a column having unique 
constraint?
 Question Submitted By :: Srikanth
I also faced this Question!!     Rank Answer Posted By  
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 1		 
no
 
Is This Answer Correct ?    11 Yes 4 No
Saurabh
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 2		 
No, because Unique constraint accepts only one null value.
 
Is This Answer Correct ?    13 Yes 3 No
Kalu
 
 
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 3		 
Yes there can be any number of NULLs. 
Remember NULL <> NULL.

So uniqueness will still be there.

Just try it out.

Maneesh
 
Is This Answer Correct ?    4 Yes 4 No
Maneesh
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 4		 
No we can not have that option in sql server
 
Is This Answer Correct ?    3 Yes 2 No
Santhoshkumar.k
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 5		 
No we cant have More than One Null in a column which is
having Unique Key Constraint. Because  Unique Key Constraint
means having a value only once in the column.
 
Is This Answer Correct ?    3 Yes 1 No
P.prabhu
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 6		 
No, I think unique constraint contain no duplicate value in 
a column. There are only contains unique value
 
Is This Answer Correct ?    0 Yes 0 No
Atikullah
 
  Re: Can we have more than one NULL in a column having unique constraint?
Answer
# 7		 
It depends upon the database on which you are working.....in SQL we can have only one value but in oracle we can have n no of values.......i did it practically.
 
Is This Answer Correct ?    0 Yes 0 No
Habibur Rahaman
 

 
 
 
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