CLR user defined aggregate function (SS2005)

Hello,
In a user defined aggregate in Visual Studio 2005 with SQL Server 2005, I
declared a private variable in the struct and initialized in the Init "event
"
of the aggregate.
In the Terminate "event" it turned out that the variable was out of scope
(null).
My first thought was that this happened as a result of reads and writes of
intermediate results of the aggregate function, where (in my case) the
private variable was not explicitly saved.
But this idea is not consistent with the Merge "event" that also uses the
private variable and there it never is out of scope.
Who can explain?
Thx.examnotes <Axford@.discussions.microsoft.com> wrote in
news:B7150A1D-2067-4377-8483-090BB56A7023@.microsoft.com:

> In a user defined aggregate in Visual Studio 2005 with SQL Server
> 2005, I declared a private variable in the struct and initialized in
> the Init "event" of the aggregate.
> In the Terminate "event" it turned out that the variable was out of
> scope (null).
> My first thought was that this happened as a result of reads and
> writes of intermediate results of the aggregate function, where (in my
> case) the private variable was not explicitly saved.
> But this idea is not consistent with the Merge "event" that also uses
> the private variable and there it never is out of scope.
How do you establish that the variable is not null in the Merge method?
In other words, are you certain that the Merge is being called. SQL will
not call Merge unless it creates a new instance of your aggregate and
runs that instance in parallell over a group in your accumulation.
Anyway, can you please post the code for your aggregate and we'll have a
look.
Also, it'd probably be better is you posted this in the sqlserver.clr
group which deals explicitly with SQLCLR issues. I will x-post this
reply to there.
Niels
****************************************
**********
* Niels Berglund
* http://staff.develop.com/nielsb
* nielsb@.no-spam.develop.com
* "A First Look at SQL Server 2005 for Developers"
* http://www.awprofessional.com/title/0321180593
****************************************
**********|||Sorry it was the Accumulate event where the private variable was in scope. S
o
probably the Merge event will set it to null also. Can I enforce thecall to
Merge in some way?
I cannot find a group sqlserver.clr.
Thanks for the reply.
"Niels Berglund" wrote:

> examnotes <Axford@.discussions.microsoft.com> wrote in
> news:B7150A1D-2067-4377-8483-090BB56A7023@.microsoft.com:
>
>
> How do you establish that the variable is not null in the Merge method?
> In other words, are you certain that the Merge is being called. SQL will
> not call Merge unless it creates a new instance of your aggregate and
> runs that instance in parallell over a group in your accumulation.
> Anyway, can you please post the code for your aggregate and we'll have a
> look.
> Also, it'd probably be better is you posted this in the sqlserver.clr
> group which deals explicitly with SQLCLR issues. I will x-post this
> reply to there.
>
> Niels
> --
> ****************************************
**********
> * Niels Berglund
> * http://staff.develop.com/nielsb
> * nielsb@.no-spam.develop.com
> * "A First Look at SQL Server 2005 for Developers"
> * http://www.awprofessional.com/title/0321180593
> ****************************************
**********
>|||examnotes <Axford@.discussions.microsoft.com> wrote in
news:FC2366AE-AFFD-4AD9-8E03-680568F1C497@.microsoft.com:

> Sorry it was the Accumulate event where the private variable was in
> scope. So probably the Merge event will set it to null also. Can I
> enforce thecall to Merge in some way?
OK, so in Accumulate the variable is OK, but in Terminate it is null -
is that correct? If so, please post the code for your UDA. AFAIK, you
can not force a call for Merge.

> I cannot find a group sqlserver.clr.
Do a refresh of your newsgroup list - that should make it available to
you (microsoft.public.sqlserver.clr).
Niels
****************************************
**********
* Niels Berglund
* http://staff.develop.com/nielsb
* nielsb@.no-spam.develop.com
* "A First Look at SQL Server 2005 for Developers"
* http://www.awprofessional.com/title/0321180593
****************************************
**********|||Here you go with the code (it is from Microsoft samples):
[Serializable]
[Microsoft.SqlServer.Server.SqlUserDefinedAggregate(
Format.UserDefined,MaxByteSize=8000, IsInvariantToNulls=true,
IsInvariantToDuplicates = false, IsInvariantToOrder=true,
IsNullIfEmpty=true)]
public struct Concatenate : IBinarySerialize
{
private string delimeter;
private StringBuilder intermediateResult;
public void Init()
{
delimeter = "-";
intermediateResult = new StringBuilder();
}
public void Accumulate(SqlString value)
{
if (value.IsNull)
return;
intermediateResult.Append(value.Value).Append(delimeter);
}
public void Merge(Concatenate other)
{
intermediateResult.Append(other.intermediateResult).Append(delimeter);
}
public SqlString Terminate()
{
string output = string.Empty;
if (this.intermediateResult != null
&& this.intermediateResult.Length > 0)
{
output = this.intermediateResult.ToString(0,
this.intermediateResult.Length - 1);
}
return new SqlString(output);
}
#region IBinarySerialize Members
void IBinarySerialize.Read(System.IO.BinaryReader r)
{
intermediateResult = new StringBuilder(r.ToString());
}
void IBinarySerialize.Write(System.IO.BinaryWriter w)
{
w.Write(intermediateResult.ToString());
}
#endregion
}
"Niels Berglund" wrote:

> examnotes <Axford@.discussions.microsoft.com> wrote in
> news:FC2366AE-AFFD-4AD9-8E03-680568F1C497@.microsoft.com:
>
> OK, so in Accumulate the variable is OK, but in Terminate it is null -
> is that correct? If so, please post the code for your UDA. AFAIK, you
> can not force a call for Merge.
>
> Do a refresh of your newsgroup list - that should make it available to
> you (microsoft.public.sqlserver.clr).
> Niels
> --
> ****************************************
**********
> * Niels Berglund
> * http://staff.develop.com/nielsb
> * nielsb@.no-spam.develop.com
> * "A First Look at SQL Server 2005 for Developers"
> * http://www.awprofessional.com/title/0321180593
> ****************************************
**********
>