Question

I have a table with 2 columns have same name

ValueA  ValueB  ValueA
12      Yes     
        No      NULL
20      Yes    
0       No      0
3       No      3

Logic is that

• when ValueA is ''
• and ValueB is 'No'
• then ValueA in second column should be '' (not NULL)

I wrote this case statement but it gives me NULL instead of ''

Case when ValueB ='No' then convert(varchar(25), ValueA)
when ValueB ='No' and ValueA ='' then ''
else ''
end

even if I write

Case when ValueB
when 'No' then convert(varchar(25), ValueA) 
else ''
end

both of above code gives me same results

How can I replace or remove NULL with '' in second ValueA column?

Answer 1

I hope i understand the question correct, you can use coalesce or isnull to replace null values.

This could be your case statement:

case when ValueB = 'Yes' then '' 
     when ValueB = 'No' then coalesce(cast(ValueA as varchar(25)), '') 
else null     end