Select statement help

[pseudosig]

I have a question:

If I have two tables in Oracle, say T1 and T2, and they have the following properties:

T1
  c1  c2   c3
 ______________
| A | 1 | alpha|
| B | 2 | beta |
| C | 3 | zeta |


T2
  c1  c2  c4
 _____________
| B | 2 | doh |

Now my problem: I want to have a single select statement such that it returns 4 columns, namely T1.c1, T1.c2, T1.c3, T2.c4. It should return all the rows from T1.

T2.c4 should return either null or its actual value from T2 if (T1.c1 = T2.c1 AND T1.c2 = T2.c2).


So the sample output of this select statement would be:

Select ...

  c1  c2   c3    c4
 ____________________
| A | 1 | alpha| null|
| B | 2 | beta | doh |
| C | 3 | zeta | null|


Thanks in advance!

[gandolf989]

SELECT t1.c1, t1.c2, t1.c3, NVL(t2.c4, 'null') c4
  FROM t1
  LEFT OUTER JOIN t2
    ON t1.c1 = t2.c1
   AND t1.c2 = t2.c2;

Is this what your teacher wanted???

[pseudosig]

Actually, it's for my work... but thanks though!

[marist89]

SELECT t1.c1, t1.c2, t1.c3, NVL(t2.c4, 'null') c4
  FROM t1
  LEFT OUTER JOIN t2
    ON t1.c1 = t2.c1
   AND t1.c2 = t2.c2;

Is this what your teacher wanted???

LOL!!