Outer join query in Oracle using the (+) sign

This post will show you how to create outer join query in Oracle using the (+) sign rather than LEFT OUTER JOIN, RIGHT OUTER JOIN, and FULL OUTER JOIN clause, since Oracle 8 didn't know them.
It is simple to do this work.Assume we have two tables (T1 and T2) with the structure is shown below:
Table T1Column Name Data Type----------- ----------A intR int
SQL> create table T1 ( A int, R int );
SQL> insert into T1 (A, R) values (1, 1);
SQL> insert into T1 (A, R) values (3, 3);
SQL> select * from T1;
A R
----------
1 1
3 3
Table T2Column Name Data Type----------- ----------B intR int
SQL> create table T2 ( R int, B int );
SQL> insert into T2 (R, B) values (2, 2);
SQL> insert into T2 (R, B) values (3, 4);
SQL> insert into T2 (R, B) values (4, 4);
SQL> select * from T2;
R B---- ----
2 2
3 4
4 4
I. LEFT OUTER JOIN
Here is the script to create left outer join query.
select * from T1, T2whereT1.R = T2.R (+);
That script will produce the following output:
A R R B
---- ---- ---- ----
1 1
3 3 3 4
The same result will be produced when we use the following script (in Oracle 9i)
select * from T1left outer join T2on T1.R = T2.R;

II. RIGHT OUTER JOIN
Here is the script to create right outer join query.
select * from T1, T2whereT1.R (+) = T2.R;
That script will produce the following output:
A R R B
---- ---- ---- ----
2 2
3 3 3 4
4 4
The same result will be produced when we use the following script (in Oracle 9i)
select * from T1right outer join T2on T1.R = T2.R;
III. FULL OUTER JOIN
To create full outer join using (+) sign, we need combine two queries above using UNION, like this:
select * from T1, T2whereT1.R = T2.R (+);
UNION
select * from T1, T2whereT1.R (+) = T2.R;
The output is below:
A R R B
---- ---- ---- ----
1 1
3 3 3 4
2 2
4 4
In Oracle 9i, we can do it with the following script.
select * from T1full outer join T2on T1.R = T2.R;