Parameter query ASSERT

markus@throun.is
Tuesday, August 20, 1996

Environment: MSVC++ 4.2 / (NT 3.51 & W95)

I created a parameter query in Access with one parameter. When opening =
it in Access
I get prompted for the parameter. But using a CDaoRecordset derived =
class with one parameter to access this query doesn't work. I can open =
the underlying table directly,
but not through the parameter query.

I create the query using the following code:

    COleVariant varID( "zz" );
    CDaoQueryDef MyQuery( pActiveDB );
    MyQuery.Open( "" );
    MyQuery.SetParamValue( "ID", varID );		// Query criteria is "field =
<> ID"

    pMyRecSet->Open( &MyQuery, dbOpenDynaset );
    pMyRecSet ->m_nFields =3D MyQuery.GetFieldCount();
    pMyRecSet ->m_nParams =3D MyQuery.GetParameterCount();

MyQuery returns 92 fields and 1 parameter which is correct.

When trying to look up records in pMyRecSet using MoveFirst() I get a =
Debug
Assertion Failure in daocore.cpp line 464. MoveFirst() calls Move() =
which in turn calls
GetDataFixupNulls() and there the exception is thrown when performing =
the following
instruction:

void CDaoRecordset::GetDataAndFixupNulls()
{
    ...
    SCODE scode =3D m_pICDAORecordsetGetRows->GetRows(
        0, m_nFields, m_prgDaoColBindInfo,
        m_cbFixedLengthFields, &m_DaoFetchRows);

    // Check for GetRows specific errors
    //  This is necessary as ICDAORecordset::GetRows
    //  errors are not appended to DAO errors collection
    if (FAILED(scode))
        ThrowGetRowsDaoException(scode);    // scode=3D-2147024809
    ...
}

An exception with error code -2147024809 is thrown and I can't figure =
out what it means.
A break occurs as a result in daocore.cpp line 464 when trying to load =
the error text
associated with this error.

----------
Markus Sveinn Markusson, Engineer
Throun Ltd, Hofdabakka 9, IS-112 Reykjavik
Tel. (354) 587-6788, Fax (354) 567-4265
e-mail: markus@throun.is

---

Jim Leavitt -- jimll@halcyon.com
Saturday, August 24, 1996

Markus:

I created a parameter query in Access with one parameter. When opening =
it in Access
I get prompted for the parameter.=20

If I understand, you've created a CDaoRecordset based on the Access =
query def. That's my preferred method too.

But using a CDaoRecordset derived class with one parameter to access =
this query doesn't work. I can open the underlying table directly, but =
not through the parameter query.

Here's the method I use...

1) Create the dao recordset with class wizard based off your querydef in =
access. It appears you've already done that.
2)  Declare a variable of the DaoRecordset... In my case this is a =
COrderSet...
COrderSet theOrders(((CInspectorApp *) AfxGetApp())->m_pDB);
3) Assign values to the parameters... there are three in this recordset
	theOrders.m_theCustomer =3D (long) nCustomerNo;	1st parameter
	COleDateTime myStartDate(nYear,nMonth,1,0,0,0);
	COleDateTime myEndDate(nYear,nMonth,nLastDay,0,0,0);
	theOrders.m_StartDate =3D myStartDate;		2nd parameter
	theOrders.m_EndDate =3D myEndDate;	3rd parameter
4) Now open the recordset...
	if (theOrders.IsOpen())
			theOrders.Requery();
		else
			theOrders.Open();
5)  do you stuff. (If you want an exact record count, you have to =
MoveLast and then MoveFirst)
6)  Close the recordset if you're done with it.

Jim Leavitt

---

Mike Blaszczak -- mikeblas@nwlink.com
Tuesday, August 27, 1996

At 11:08 AM 8/20/96 +-100, you wrote:

>    // Check for GetRows specific errors
>    //  This is necessary as ICDAORecordset::GetRows
>    //  errors are not appended to DAO errors collection
>    if (FAILED(scode))
>        ThrowGetRowsDaoException(scode);    // scode=-2147024809
>    ...
>}

>An exception with error code -2147024809 is thrown and I can't figure out
what it means.
>A break occurs as a result in daocore.cpp line 464 when trying to load the
error text
>associated with this error.

Try calling GetErrorMessage() or ReportError() on the exception:

   try
   {
      // do that stuff you were talking about
   }
   catch (CException* pEx)
   {
      pEx->ReportError();
      pEx->Delete();
   }

You'll get actual, real error text in plain language.

.B ekiM
http://www.nwlink.com/~mikeblas/
These words are my own. I do not speak on behalf of Microsoft.

---

| Вернуться в корень Архива |