Re: Unexpected ADO properties - Mailing list pgsql-odbc

Hye Jeff,

You are right when you say that : PostgreSQL has no notion of "autoincrement"

However, we are talking of pgsql-odbc.

ODBC is an abstract layer that "hides" databases technical details.
Even though PostgreSQL uses some "technical details" for giving the "autoincrement" behavior, on the (ODBC) user point
ofview, it still is an "autoincrement" behavior. 

Therefore, concerning PostgreSQL it is the pgsql-odbc responsability to manage this "technical detail".

Technically speaking, pgsql-odbc could in fact query PostgreSQL's catalog to check whether a serial field has its
DEFAULTset with a 'nextval' and return, in such case, to ODBC user that it IS an autoincrement field. 

Best regards


--- "Jeff Eckermann" <jeff_eckermann@yahoo.com> wrote:

From: "Jeff Eckermann" <jeff_eckermann@yahoo.com>
Date: Mon, 22 Aug 2005 13:54:03 +0930
To: pgsql-odbc@postgresql.org
Subject: Re: [ODBC] Unexpected ADO properties

"Bernard Henry Voynet" <bhv@quebecemail.com> wrote in message
news:20050820115339.D2B57834@dm21.mta.everyone.net...
> Hello
> I  am  working  on  a project that access databases through ADO
> over ODBC and must now include PostgreSQL.
>
> The  code  of  this  project  needs  to  know  about the fields
> caracteristics like whether or not it is:
> - a primary key
> - an autoincrement key
> - nullabble
> - updatable
> - etc..
>
> For   this   I   use   the  ADO  properties  that  give  theses
> informations.
>
> For a Jet database I get (for example):
> serialkey
>     Type = adInteger
>     DefinedSize = 4
>     Precision = 10
>     NumericScale = 255
>     Status = adRecOK
>     Attributes = adFldFixed
>     Properties (9)
>          BASECATALOGNAME (adVarWChar) = (Null)
>          BASECOLUMNNAME (adVarWChar) = serialkey
>          BASESCHEMANAME (adVarWChar) = (Null)
>          BASETABLENAME (adVarWChar) = genericfields
>          CALCULATIONINFO (adVarBinary) = (Null)
>          ISAUTOINCREMENT (adBoolean) = True
>          KEYCOLUMN (adBoolean) = True
>          OPTIMIZE (adBoolean) = False
>          RELATIONCONDITIONS (adVarBinary) = (Null)
>
> However, with  PostgreSQL  8.0.3  (psqlodc 08.00.0102), I don't get what
> is expected.
>
> When I declare le serialkey field as as SERIAL PRIMARY KEY, instead of the
> expected result, I get:
> serialkey
>     Type = adInteger
>     DefinedSize = 4
>     Precision = 10
>     NumericScale = 255
>     Status = adRecOK
>     Attributes = adFldUnknownUpdatable, adFldFixed, adFldIsNullable,
> adFldMayBeNull
>     Properties (9)
>          BASECATALOGNAME (adVarWChar) = (Null)
>          BASECOLUMNNAME (adVarWChar) = serialkey
>          BASESCHEMANAME (adVarWChar) = (Null)
>          BASETABLENAME (adVarWChar) = genericfields
>          CALCULATIONINFO (adVarBinary) = (Null)
>          ISAUTOINCREMENT (adBoolean) = False
>          KEYCOLUMN (adBoolean) = True
>          OPTIMIZE (adBoolean) = False
>          RELATIONCONDITIONS (adVarBinary) = (Null)
>
> Where both:
> - Attributes
> - ISAUTOINCREMENT
> Are not correct since serialkey is a non nullable serial key

PostgreSQL has no notion of "autoincrement".  The "serial" type is an
equivalent implementation, but is not actually a type in itself; it is an
integer type with a default value drawn from a sequence.

The values reported in the "attributes" are certainly wrong; this is
definitely a bug somewhere, but where, I don't know enough to say.  Perhaps
someone more knowledgeable can help.

>
> Would you have any idea on this problem ?
> And any help to get the right values ?
>
> Best regards
>
>
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