How to return successfully found values ​​if no other values ​​are found in the database?

Question

MySQL

For example, there is a request:

SELECT s1.id AS sq_id, s1.name AS t1_name, s2.id AS t2_id, s2.name AS t2_name 
FROM `list` AS s1 
INNER JOIN `list` AS s2 ON s2.name = "XXX"
WHERE s1.name = "YYY";

In this case, if XXX or YYY is not found, then a completely empty response is returned. How to make a query so that if one of the conditions is found, then return at least it? Thank you!

Answer 1

MySQL OUTER JOIN is not supported. can be emulated via LEFT JOIN ... UNION ... RIGHT JOIN.
Isn't it easier to choose separately for XXX and separately for YYY?

Answer 2

I do not understand why join is here?

SELECT s1.id AS sq_id, s1.name AS t1_name  
FROM `list` AS s1 
WHERE s1.name IN ("YYY", "XXX")