Re: convert integer to bool implicitly

I got it working.
This has been bothering me for a long time, but now that it was listed
as an official bug in my system, I had to deal with it.

I'll post the solution under a new post, because I think this will help
a lot of people.

Sim Zacks wrote:
> I know I can do it explicitly, I need to do it implicitly.
> I am having a problem with a Microsoft Access front-end , that uses -1
> as true and 0 as false.
> I have everything worked around all the places where I could find it by
> using a cbool(), but this doesn't work with filters, which probably call
> a "select where field =-1 or =0." automatically by access.
>
> I get an ODBC error saying that "Operator does not exist: boolean=integer.
>
> I would like to create the implicit conversion, so that it works both
> without the cbool from now on, and that filters should work fine.
> I have tried a number of different ODBC settings, and no matter what
> setting there is always one problem or another that has to be overcome.
> I can get it all to work if I put a Before Insert and Update trigger and
> change the -1 to true, but I would have to do that for every boolean
> field in my application. It would be a lot easier and make sense
> system-wise to implicitly convert the integer to bool.
>
> Andreas Kretschmer wrote:
>> Sim Zacks <sim@compulab.co.il> schrieb:
>>
>>> How easy would it be to write a small type extension to have integer
>>> automatically convert to bool?
>>> For example, I want an implicit conversion that 0 is false and
>>> everything else is true.
>>
>> test=# \d foo;
>>       Table "public.foo"
>>  Column |  Type   | Modifiers
>> --------+---------+-----------
>>  val    | integer |
>>
>> test=# select * from foo;
>>  val
>> -----
>>    0
>>    1
>>    2
>>    3
>> (4 rows)
>>
>> test=# select val::bool from foo;
>>  val
>> -----
>>  f
>>  t
>>  t
>>  t
>> (4 rows)
>>
>>
>>> Is this C programming or can you do it with a local procedural language?
>>
>> You can use regular casts.
>>
>>
>> HTH, Andreas