sql - Multiple FULL OUTER JOIN on multiple tables

Question

I have multiple outer joins

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
)

Now the last join is having a problem, its repeating when month of A is more than B but if B has more month that A we have OUTER JOIN in C with month of A which now repeats, so I guess having a FULL OUTER JOIN within two table might solve the problem?? Any indepth links??

Sample Data(Incorrect)

╔════════════╦═════════╦═════════════╗
║  Revenue   ║ Budget  ║ ActualMonth ║
╠════════════╬═════════╬═════════════╣
║     6.9172 ║ 3.5046  ║ Jan         ║
║     7.3273 ║ 3.7383  ║ Feb         ║
║     7.3273 ║ 3.9719  ║ Mar         ║
║     7.2726 ║ 4.2056  ║ Apr         ║
║     7.2595 ║ 6.7757  ║ May         ║
║     7.2726 ║ 6.7757  ║ Jun         ║
║     0.41   ║ 0.00    ║ Jul         ║
║     0.41   ║ 0.00    ║ Aug         ║
║     0.41   ║ 0.00    ║ Sep         ║
║     0.41   ║ 0.00    ║ Oct         ║
║     7.4696 ║ 0.00    ║ Nov         ║
║     7.4696 ║ 0.00    ║ Dec         ║
║     0.00   ║ 9.3457  ║ Sep         ║
║     0.00   ║ 16.3551 ║ Dec         ║
║     0.00   ║ 6.3084  ║ Jul         ║
║     0.00   ║ 14.0186 ║ Oct         ║
║     0.00   ║ 16.3551 ║ Nov         ║
║     0.00   ║ 6.1915  ║ Aug         ║
╚════════════╩═════════╩═════════════╝

Correct Data

╔════════════╦═════════╦═════════════╗
║  Revenue   ║ Budget  ║ ActualMonth ║
╠════════════╬═════════╬═════════════╣
║     6.9172 ║ 3.5046  ║ Jan         ║
║     7.3273 ║ 3.7383  ║ Feb         ║
║     7.3273 ║ 3.9719  ║ Mar         ║
║     7.2726 ║ 4.2056  ║ Apr         ║
║     7.2595 ║ 6.7757  ║ May         ║
║     7.2726 ║ 6.7757  ║ Jun         ║
║     0.41   ║ 6.3084  ║ Jul         ║
║     0.41   ║ 6.1915  ║ Aug         ║
║     0.41   ║ 9.3457  ║ Sep         ║
║     0.41   ║ 14.0186 ║ Oct         ║
║     7.4696 ║ 16.3551 ║ Nov         ║
║     7.4696 ║ 16.3551 ║ Dec         ║
╚════════════╩═════════╩═════════════╝

question from:https://stackoverflow.com/questions/16167902/multiple-full-outer-join-on-multiple-tables

Answer 1

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 ISNULL(A.month, B.month) = C.month
)