PRB: SQL Server Stored Procedure's Out Parameters Can Return Incorrect Values

ID: Q224591

The information in this article applies to:

SYMPTOMS

When using ADO and the default server side cursor is out, parameters return NULL values.


CAUSE

ADO doesn't fill in the out parameters for a recordset created using adUseServer (server side cursor) until the returned recordset is closed.


RESOLUTION

Use one of the following methods to get the correct output values from the stored procedure.

  1. Select Client side server adUseClient. In the code below insert the following line just before the comm->Execute() call.



    2. 
	conn->CursorLocation=adUseClient;
  2. Close the returned recordset before getting the value of the output parameter. In the code below insert the following line just before obtaining the parameter values.
    
     rs->Close();



STATUS

This behavior is by design.


MORE INFORMATION

Steps To Reproduce Behavior

  1. In the SQL Server 7.0 Query Analyzer select the test database Pubs.


  2. Create the following stored procedure. This stored procedure returns a recordset and an out parameter count.


    3. 
if exists (select * from sysobjects where id = object_id(N'[dbo].[GetJobs]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop proc GetJobs
go
create proc GetJobs @id as int, @count as int [out] as
begin
	Select @count = Count(*) from jobs where job_id >@id
	Select * from jobs where job_id >@id
end
go


  3. Use VC App Wizard to create a new console application and modify the code as follows:


    4. 
#include "stdafx.h"
#include "stdio.h"
#import "C:\PROGRA~1\COMMON~1\System\ado\msado15.dll" no_namespace rename ("EOF", "EOF2")

struct InitOle {
  InitOle()  { ::CoInitialize(NULL); }
  ~InitOle() { ::CoUninitialize();   }
} _init_InitOle_;

int main(int argc, char* argv[])
{
	_variant_t varErr((long)0, VT_ERROR);
	_CommandPtr comm(__uuidof(Command));
	_ConnectionPtr conn(__uuidof(Connection));

	_bstr_t connstr="Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=pubs;Data Source=(local)";
	conn->Open(connstr, "", "", adConnectUnspecified);
	comm->ActiveConnection=conn;
	comm->CommandText="GetJobs";
	comm->CommandType = adCmdStoredProc ; 
	comm->Parameters->Refresh();
	_variant_t recs;

	comm->Parameters->Item[_variant_t((short)1)]->Value= _variant_t((long)5);
	_RecordsetPtr rs = comm->Execute(&recs, &vtMissing,adCmdStoredProc); 

	_variant_t recordcount= comm->Parameters->Item[_variant_t((short)2)]->Value;

	printf("recordcount = %li\n", (long)recordcount);
	return 0;
}

  4. Change the Datasource, User ID and password in the connection string above.




The recordcount variant that the above code returns is of type VT_NULL rather than the number of records that the stored procedure returns.

Additional query words: 


Keywords          : kbADO kbDatabase kbVC kbGrpVCDB 
Version           : WINDOWS:1.5,2.0
Platform          : WINDOWS 
Issue type        : kbprb

Last Reviewed: April 30, 1999