Question

I have the following syntax on my SELECT Statement:

CONCAT(first_name, " ", COALESCE(middle_initial), " ", last_name) AS full_name

Obviously, what I get is the following:

For first_name='John' and middle_initial='A.' and last_name='Smith' 
I get 'John A. Smith'

That is fine and is the desired result.

But I get an extra space for the following data (which I clearly understand why):

For first_name='John' and middle_initial='' and last_name='Smith' 
I get 'John  Smith'

Is there a way with COALESCE() to append ” ” if the condition returns a non-null value?

Thank you.

Answer 1

When middle_initial has ”, you would want to:

SELECT CONCAT(first_name, ' ', 
   CASE
      WHEN middle_initial is null OR middle_initial = '' then ''
      ELSE CONCAT(middle_initial, ' ')
   END
   , last_name) AS full_name

SQLFiddle Example

COALESCE is used for checking NULL values, not handling empty strings, ”