SQL select return 0 if no records found, else return value

Question

I am now using Microsoft SQL, my code is:

   SELECT TOP 1 
   [avail]
   FROM [table1]
   where [name] = \'abc\'
   order by [datetime] desc

I

Answer 1

Try to use COALESCE. It selects the data from the first argument that has a nonnull value. If avail is not null, return [avale], otherwise return "Not Found"

SELECT COALESCE(avail, 'Not Found')
FROM table1
WHERE name = 'abc'
ORDER BY datetime desc

You can read about COALESCE in https://docs.microsoft.com/en-us/sql/t-sql/language-elements/coalesce-transact-sql