Re: [GENERAL] Making NULLs visible.

> At 18:36 +0200 on 9/10/98, Bruce Momjian wrote:
>
>
> > I am always looking for suggestions on how to display nulls.  It is on
> > the TODO list.
>
> Here is my suggestion, admittedly a bit cheeky:
>
> Implement an NVL function - one that dictates a NULL in a field and
> converts it to whatever value is required.
>
> Then, anybody who wants psql to display a null function can decide what is
> to be displayed on a per-query basis:
>
> SELECT a, nvl(b,'I am null!'), c
> FROM tab
> WHERE...
>
> Will give something like:
>
> a   |  ?column?  | c
> ====|============|=====
> 10  | Moses      | 100
> 20  | Solomon    | 200
> 30  | I am null! | 300
> 40  | David      | 400
> 50  | I am null! | 500
>
> And so on... So, if someone wants \N, he'll put '\\N' in the NVL function,
> and if they want NULL, they'll put 'NULL', etc.
>
> NVL will be usefull for lots of stuff... Not only for this...

Yes, this is a nice feature.  Ingres has it as isnull(val, 'string'), as
you demonstrated.

I will add it to the TODO list.

--
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026