多个表上的多个完整外部连接

I have multiple outer joins

我有多个外部连接

SELECT  A.column2
        , B.column2
        , C.column2
FROM 
(
    (SELECT month, column2 FROM table1) A
    FULL OUTER JOIN
    (SELECT month, column2 FROM table2) B on A.month= B.month
    FULL OUTER JOIN 
    (SELECT month, column2 FROM table3) C on A.month= C.month
)
SELECT