How to check if WHERE = value does not exist and make it zero by default?

My goal is to check if lineId's value exists. If not, it has to be zero by default.
Here is my datas:

For example:

SELECT lineId from table_name WHERE lineId = 80

There is no lineId = 80, then I want to see that lineId = 0 records.

Thanks, sincerely :)

Another method:

SELECT lineId 
FROM table_name 
WHERE lineId = 80

UNION ALL

SELECT lineId 
FROM table_name 
WHERE lineId = 0
  AND NOT EXISTS
      ( SELECT 1 
        FROM table_name 
        WHERE lineId = 80
      ) ;

And similar with a CTE:

WITH cte AS
  ( SELECT lineId 
    FROM table_name 
    WHERE lineId = 80
  )

SELECT * 
FROM cte

UNION ALL

SELECT lineId 
FROM table_name 
WHERE lineId = 0
  AND NOT EXISTS
      ( SELECT *
        FROM cte
      ) ;

StackExchange Database Administrators Q#316505, answer score: 6