Re: What's + 0 does after a column name when creating view

From: Rene Nyffenegger <rene.nyffenegger_at_gmx.ch>
Date: Thu, 9 Jun 2005 19:22:56 +0000 (UTC)
Message-ID: <d8a4ug$4sh$3@klatschtante.init7.net>

On 2005-06-09, andyho99_at_yahoo.com <andyho99_at_yahoo.com> wrote:
> Hi,
>
> I was wondering why people put "+ 0" after a column when creating view.
>
>
> For example,
>
> CREATE OR REPLACE FORCE VIEW APPS.PER_ADDRESSES_V (a, b, c) as
> select a,
> b + 0 b,
> c

It forces a varchar to be a number:

create table foo (

  a varchar2(5),
  b varchar2(5),
  c varchar2(5)

);

create view vw_foo_1 as
select a,b,c from foo;

create view vw_foo_2 as
select a,b+1 b, c from foo;

desc vw_foo_1;

 Name Null? Type

• -------- -----------

 A               VARCHAR2(5)
 B               VARCHAR2(5)
 C               VARCHAR2(5)

desc vw_foo_2;

 Name Null? Type

• ------------

 A               VARCHAR2(5)
 B               NUMBER
 C               VARCHAR2(5)

It goes with(out) saying that this is bad practise.

hth
Rene

-- 
  Rene Nyffenegger
  http://www.adp-gmbh.ch/

Received on Thu Jun 09 2005 - 14:22:56 CDT