Left join but maintain values where NULL may result in Microsoft SQL

Question

I have two tables:

Table A:

id names
1   a
2   b
3   c

and Table B:

id names
1   x
2   y

I'd like to perform a left join of Table B on Table A that results in the following table:

id names
1   x
2   y
3   c

How can I do this in Microsoft SQL?

Answer 1

You could use COALESCE :

SELECT a.id, COALESCE(b.name, a.name) AS name
FROM tab1 a
LEFT JOIN tab2 b 
  ON a.id = b.id

Answer 2

I think you just want coalesce() :

select a.id, coalesce(b.name, a.name) as name
from a left join
     b
     on a.id = b.id;