FreeTDS Development Group

[Alberto Pulvirenti <alberto.pulvirenti AT crowdengineering.com>]

Hello,

2012/9/27 James K. Lowden <jklowden AT freetds.org>

> On Tue, 25 Sep 2012 18:15:38 +0200
> Alberto Pulvirenti <alberto.pulvirenti AT crowdengineering.com> wrote:
>
> > > Session properties aren't set by dbopen().  They're set via
> > > T-SQL's SET command.  Read up on that, and on @@options.  (Nowadays
> > > there's a function to query session properties individually, not
> > > just as a bit mask.)
> >
> > This last paragraph I didn't fully understand.
>
> What may not be clear is that the problem you're seeing doesn't
> manifest itself when you first open the connection.  It shows up when
> you issue that particular query.  A simple query like
>
>         SELECT 1 as 'one'
>
> will not fail.  But one that requires e.g. CONCAT_NULL_YIELDS_NULL
> will.
>

This is perfectly clear. Then, something which is sent by my dbopen()
invocation maybe triggers some query that relies on this.
I am just wanrdering what can this be, which is not done by the executable
"tsql".


>
> CONCAT_NULL_YIELDS_NULL is a session property.  Session properties in a
> T-SQL session are set using the T-SQL SET command, cf.
> http://msdn.microsoft.com/en-us/library/ms190356.aspx.  Among the many
> arcane things affected by session properties are the ability to create
> indexed views and the ability to *use* an existing index of an indexed
> view, cf. "Requirements for the CREATE INDEX Statement" at
> http://msdn.microsoft.com/en-us/library/aa933148(v=SQL.80).aspx.
>
> > In any case, I suppose that I can issue such a SET command only once
> > the DBPROCESS is properly initialized after dbopen().
>
> English is a little ambiguous here.  You can issue any number of SET
> commands for the duration of the session, just as any query, after
> dbopen() and before dbclose().
>

I am very sorry since maybe I don't manage to express myself clearly enough.
Anyway, that's the point. My application fails when I call dbopen().
Then, whatever needed to solve this problem I need to apply BEFORE calling
dbopen(). That's what is driving me crazy.

Thanks,

Alberto


>
> HTH.
>
> --jkl
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