SQL Join result table as alias

Question

Is there a way to give a result table of a join an alias?

Example query:

SELECT *
FROM t1
JOIN t2
ON t1.num = t2.num
AS result;

Answer 1

Yes!

select result.* 
from (SELECT *
    FROM t1
    JOIN t2
    ON t1.num = t2.num) result

You do need to watch where you've got columns of the same name in both the inner tables; you'll get an ambiguous column error for num in the results table. Instead of select * its a good idea to pick out the ones you want.

Answer 2

You can make it a table expression (sub-query) and give that an alias, but in your simple example I don't see what benefit it could add. I assume you're going to use this in a more complex query

SELECT *
FROM (
    SELECT t1.id, t1.name, t2.category, t2.subcategory
    FROM t1
    INNER JOIN t2 ON t1.id=t2.id
) AS result
LEFT JOIN t3 ON result.id=t3.id

Answer 3

SELECT result.* FROM 
(SELECT *
FROM t1
JOIN t2
ON t1.num = t2.num) AS result;