SQL - Full Outer Join

A “Full Outer Join” is interpreted as :

• show me all data from the left table and all the data from the the right table regardless of any matches.
• or give me every row from both tables, regardless of whether or not it has a match in the other table

It does then :

1. an outer join of the two tables
2. an anti join of the two tables
3. then an UNION ALL of the two result data set

gerardnico@orcl>select table1.id "ID_table1", table2.id "ID_table2"
  2        FROM table1 FULL OUTER JOIN table2
  3       ON  table1.id = table2.id;

The syntax below is not correct:

SELECT table1.id "ID_table1", table2.id "ID_table2"
FROM table1, table2
WHERE table1.id (+)= table2.id (+);

You will get this message:

ORA-01468: a predicate may reference only one outer-joined table
01468. 00000 -  "a predicate may reference only one outer-joined table"
*Cause:    
*Action:
Error at Line: 55 Column: 19

On workaround is to make two outer join on each table and to join the data set with an union such as:

SELECT
  table1.id "ID_table1",
  table2.id "ID_table2"
FROM
  table1,
  table2
WHERE
  table1.id = table2.id (+)
UNION
SELECT
  table1.id "ID_table1",
  table2.id "ID_table2"
FROM
  Table1,
  Table2
WHERE
  table1.id (+) = table1.id 

The source table:

The Result:

ID_table1  ID_table2
---------- ----------
A          A
B          B
D
           C