Aggiungere i risultati da diversi COUNT interroga

Question

Sto cercando di prendere la somma di più conta in una query:

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

mi manca qualcosa qui. Ottengo l'errore di sintassi.

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

Un altro (non so se supportato con MySQL, anche se - lavora a 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 
    )