
Hiroshi Inoue wrote:
> Tom Lane wrote:
> > 
> > Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > > What the driver has suffered from is to get the
> > > fields' info of a query result or the parameters'
> > > info of a statement. The info is needed even before
> > > the execution of the statement(i.e it's only prepared).
> > 
> > Hm.  Are you saying that you would like PREPARE to send back a
> > RowDescription ('T') message?
> 
> I'm not sure if PREPARE should return the info directly.
> Maybe it should be returned only when it is requested.
> 
> > Or is there more to it than that?
> 
> More detailed field info is needed anyway.
> For example the RowDescription contains neither 
> the base column name, the table name nor the
> schema name currently and so the current odbc
> driver couldn't return the info correctly.

But it only needs that info to do system catalog lookups for type, length etc.
Imho the target should be to not need catalog lookups, but get all needed info 
from the 'T' message, no?

> The ODBC function SQLDescribeCol or SQLColAttribute
> requires various kind of fields' info.

RETCODE SQL_API SQLDescribeCol(
    HSTMT       hstmt,
    UWORD       icol,
    UCHAR  FAR *szColName,
    SWORD       cbColNameMax,
    SWORD  FAR *pcbColName,
    SWORD  FAR *pfSqlType,
    UDWORD FAR *pcbColDef,
    SWORD  FAR *pibScale,
    SWORD  FAR *pfNullable);

So you see it does not need tablename or schema.

> 
> It's almost impossible to get parameters' info
> currently. The ODBC function SQLDescribeParam
> isn't implemented yet....

Would be same as above, the 'T' message should describe input 
and output columns.

Andreas

Wed, 12 Mar 2003 10:50:29 +0100
"Zeugswetter Andreas SB SD" <ZeugswetterA@spardat.at>
Re: Roadmap for FE/BE protocol redesign
> -----Original Message-----
> From: Zeugswetter Andreas SB SD [mailto:ZeugswetterA@spardat.at] 
> 
> Hiroshi Inoue wrote:
> > Tom Lane wrote:
> > > 
> > > Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > > > What the driver has suffered from is to get the
> > > > fields' info of a query result or the parameters'
> > > > info of a statement. The info is needed even before
> > > > the execution of the statement(i.e it's only prepared).
> > > 
> > > Hm.  Are you saying that you would like PREPARE to send back a
> > > RowDescription ('T') message?
> > 
> > I'm not sure if PREPARE should return the info directly.
> > Maybe it should be returned only when it is requested.
> > 
> > > Or is there more to it than that?
> > 
> > More detailed field info is needed anyway.
> > For example the RowDescription contains neither 
> > the base column name, the table name nor the
> > schema name currently and so the current odbc
> > driver couldn't return the info correctly.
> 
> But it only needs that info to do system catalog lookups for 
> type, length etc.
> Imho the target should be to not need catalog lookups, but 
> get all needed info 
> from the 'T' message, no?

Maybe.

> 
> > The ODBC function SQLDescribeCol or SQLColAttribute
> > requires various kind of fields' info.
> 
> RETCODE SQL_API SQLDescribeCol(
>     HSTMT       hstmt,
>     UWORD       icol,
>     UCHAR  FAR *szColName,
>     SWORD       cbColNameMax,
>     SWORD  FAR *pcbColName,
>     SWORD  FAR *pfSqlType,
>     UDWORD FAR *pcbColDef,
>     SWORD  FAR *pibScale,
>     SWORD  FAR *pfNullable);
> 
> So you see it does not need tablename or schema.

Oh yes but SQLColAtrribute should return
such info if requested.
 
regards,
Hiroshi Inoue


Wed, 12 Mar 2003 23:32:45 +0900
"Hiroshi Inoue" <inoue@tpf.co.jp>
Re: Roadmap for FE/BE protocol redesign