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
          


        

Answer 1

One of the ways to do this could be create "anchor" table from all possible data from all three tables and then use left outer join:

select
    A.column2,
    B.column2,
    C.column2
from (
    select distinct month from table1
    union
    select distinct month from table2
    union
    select distinct month from table3
) as X
    left outer join table1 as A on A.month = X.month
    left outer join table2 as B on B.month = X.month
    left outer join table3 as C on C.month = X.month