decode

[Bloke152]

I sure im not being very bright with this one but i cant work out how its bringing up the values it is. So could someone please explain to me what this line is doing. i thought i knew but i must be wrong!

Sum(decode(a.direction,'+',a.quantity,-a.quantity))
Thanks!

 

[BJCooperIT]

It is summing a.quantity while applying a sign (a.direction)

SQL> CREATE TABLE TESTIT (QUANTITY number, DIRECTION char(1));

Table created.

SQL> INSERT INTO TESTIT VALUES (10,'+')

1 row created.

SQL> INSERT INTO TESTIT VALUES (25,'+');

1 row created.

SQL> INSERT INTO TESTIT VALUES(1,'-');

1 row created.

SQL> SELECT Sum(decode(a.direction,'+',a.quantity,-a.quantity)) RESULT
  2* FROM TESTIT A
SQL> /

    RESULT
----------
        34

SQL>

^{Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw}
Consultant Developer/Analyst Oracle, Forms, Reports & PL/SQL (Windows)
Author and Sole Proprietor of: Emu Products Plus

 

[Bloke152]

Thants great thanks, i was on the wrong track. Thanks for your help!