Select column, if blank select from another

Question

How does one detect whether a field is blank (not null) and then select another field if it is?

What I really need is a IsBlank function that works the same as IsNul

Answer 1

You can use a CASE statement for this

select 
Case WHEN Column1 = '' OR Column1 IS NULL OR LEN (TRIM (Column1))  = 0 
     THEN Column2 
     ELSE Column1 END as ColumnName
from TableName