what different between blank and null ?

Consider this solution too:

select * 
from Employee 
where [Family Name] <> ''

It will exclude null and blank values.

Simple , BLANK is a known value but NULL us unknown value

Hi @ahmed salah ,

I will provide one example from below and you could check whether it is helpful to you.

I would like to use ISNULL to include the blank and null conditions.

declare @Employee  table  
(id int,  
FamilyName varchar(20))  
  
insert into @Employee values  
(1,''),  
(2,null),  
(3,'Mary')  
  
select * from @Employee where FamilyName is null  
--id FamilyName  
--2 NULL  
  
select * from @Employee where FamilyName=''  
--id FamilyName  
--1  
  
select * from @Employee where FamilyName='' or FamilyName is null  
--id FamilyName  
--1  
--2 NULL  
  
select * from @Employee where isnull(FamilyName,'')=''  
--id FamilyName  
--1  
--2 NULL  

In your situation, you could have a try with below queries:

--option 1  
   select * from @Employee where isnull(FamilyName,'')<>''  
--option 2  
    select * from @Employee where FamilyName<>'' and FamilyName is not null  

If there is no index on FamilyName column, you could choose any of them.

If you have index on FamilyName column, you could try with option 2 because of performance benefits since isnull is one function and causes that predicate to be non-SARGable.

Best regards
Melissa

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