Dodaj wyniki z kilku COUNT odpytuje

Question

Próbuję pobrać sumę kilku powodów w jednym zapytaniu:

SELECT(
    SELECT COUNT(*) 
    FROM comments + 
    SELECT COUNT(*) 
    FROM tags + 
    SELECT COUNT(*) 
    FROM search 
) 

ja czegoś brakuje tutaj. Dostaję błąd składni.

Answer 1

SELECT (SELECT COUNT(*) FROM comments) 
    + (SELECT COUNT(*) FROM tags) 
    + (SELECT COUNT(*) FROM search) 

Answer 2

SELECT (
     SELECT COUNT(*) 
     FROM comments 
     ) + 
     (
     SELECT COUNT(*) 
     FROM tags 
     ) + 
     (
     SELECT COUNT(*) 
     FROM search 
     ) 

Answer 3

Jeszcze jedna (nie wiem, czy obsługiwane przez MySQL, chociaż - działa w SQL Server):

SELECT SUM(Counts) FROM 
    (SELECT COUNT(*) AS Counts FROM COMMENTS UNION ALL 
    SELECT COUNT(*) FROM Tags UNION ALL 
    SELECT COUNT(*) FROM Search) s 

Answer 4

SELECT SUM(ThisCount) 
    FROM (
    SELECT COUNT(*) AS ThisCount 
     FROM comments 

    UNION ALL 

    SELECT COUNT(*) AS ThisCount 
     FROM tags 

    UNION ALL 

    SELECT COUNT(*) AS ThisCount 
     FROM search 
    )