Query - Full Join

Hello experts,

I have a simple query that I can't seem to get it to work correctly.  I have a table that has just one field call "CODE".  This is query between 3 databases, so I need to be able to order them in sequence and have it ouput side by side.  All 3 databases has same table and 1 field call "CODE".

Example:

DB1          DB2            DB3
AAB1         AAB1          AAB1
BB32         NULL          BB32
CDB4         NULL          NULL
NULL         NULL          DDEF3
JJL12          JJL12           NULL

I  tried the following, but can't seem to sort correctly.

SELECT D1.CODE AS DB1, D2.CODE AS DB2, D3.CODE AS DB3
FROM  DB1.DBO.PRODUCT D1 FULL OUTER JOIN DB2.DBO.PRODUCT D2
            ON D1.CODE = D2.CODE FULL OUTER JOIN DB3.DBO.PRODUCT D3
             ON D2.CODE = D3.CODE OR D1.CODE = D3.CODE