ID: Q192014
The information in this article applies to:
The following information is from the Data Access Software Development Kit (SDK) version 2.0 OLREADME file:
IRowsetResynch is an interface defined in OLE DB 1.x that allows consumers to retrieve the current values for rows that may have been changed in the data store since retrieved. In OLE DB 2.0, IRowsetResynch is superceded by IRowsetRefresh, which provides better control over when data values are updated from the data store.
In future releases of OLE DB, a common service component will expose IRowsetRefresh over providers that currently expose only IRowsetResynch. In the interim, consumers can work with legacy providers that support only IRowsetResynch by directly calling that interface. This interface is documented here for those customers.
The following information is from the Readme.txt file:
Gets the data in the data source that is visible to the transaction for the specified row.
HRESULT GetVisibleData (
HROW hRow,
HACCESSOR hAccessor,
void * pData);
hRow [in]
The handle of the row for which to get the visible data.
This can be the handle of a row with a pending delete.
The handle of the accessor to use. If hAccessor is the handle of a null
accessor (cBindings in IAccessor::CreateAccessor was zero), then
GetVisibleData does not get any data values.
A pointer to a buffer in which to return the data. The consumer
allocates memory for this buffer.
S_OK
The method succeeded. The status of all columns bound by the accessor
is set to DBSTATUS_S_OK, DBSTATUS_S_ISNULL, or DBSTATUS_S_TRUNCATED.
An error occurred while returning data for one or more columns,
but data was successfully returned for at least one column.
A provider-specific error occurred.
pData was a null pointer and hAccessor was not a null accessor.
ITransaction::Commit or ITransaction::Abort was called and the
object is in a zombie state.
hAccessor was invalid. It is possible for a reference accessor
or an accessor that has a binding that uses provider-owned
memory to be invalid for use with this method, even if the
accessor is valid for use with IRowset::GetData or
IRowsetChange::SetData.
The specified accessor was not a row accessor.
hRow was invalid.
hRow referred to a row for which a deletion had been transmitted
to the data source.
Errors occurred while returning data for all columns. To
determine what errors occurred, the consumer checks the
status values.
The provider was unable to retrieve the visible data due
to reaching a limit on the server, such as a query execution
timing out.
DBPROP_STRONGIDENTITY was VARIANT_FALSE and hRow referred
to a row for which an insertion had been transmitted to the
data source.
The provider called a method from IRowsetNotify in the
consumer and the method has not yet returned.
The rowset was in delayed update mode and hRow referred to
a pending insert row.
E_NOINTERFACE
DB_E_BADBINDINFO
DB_E_BADORDINAL
DB_E_BADSTORAGEFLAGS
DB_E_UNSUPPORTEDCONVERSION
This method makes no logical change to the state of the object. A consumer calls GetVisibleData to retrieve the data in the data source that is visible to the transaction for the specified row. However, GetVisibleData does not affect the values in the rowset's copy of the row.
If GetVisibleData fails, the memory to which pData points is not freed but its contents are undefined. If, before GetVisibleData failed, the provider allocated any memory for return to the consumer, the provider frees this memory and does not return it to the consumer.
Gets the data in the data source that is visible to the transaction for the specified rows and updates the rowset's copies of those rows.
HRESULT ResynchRows (
ULONG cRows,
const HROW rghRows[],
ULONG* pcRowsResynched,
HROW** prghRowsResynched,
DBROWSTATUS** prgRowStatus);
cRows [in]
The count of rows to resynchronize. If cRows is zero, ResynchRows
ignores rghRows and reads the current value of all active rows.
An array of cRows row handles to be resynchronized. If cRows is zero,
this argument is ignored.
A pointer to memory in which to return the number of rows the method
attempted to resynchronize. The caller may supply a null pointer if no
list is desired. If the method fails, the provider sets *pcRowsResynched
to zero.
A pointer to memory in which to return the array of row handles the
method attempted to resynchronize. If cRows is not zero, then the
elements of this array are in one-to-one correspondence with those of
rghRows. If cRows is zero, the elements of this array are the handles of
all active rows in the rowset. When cRows is zero, ResynchRows will add
to the reference count of the rows whose handles are returned in
prghRowsResynched.
The rowset allocates memory for the handles and the client should
release this memory with IMalloc::Free when no longer needed. This
argument is ignored if pcRowsResynched is a null pointer and must not be
a null pointer otherwise. If *pcRowsResynched is 0 on output or the
method fails, the provider does not allocate any memory and ensures that
*prghRowsResynched is a null pointer on output.
A pointer to memory in which to return an array of row status values.
The elements of this array correspond one-to-one with the elements of
*prghRowsResynched. If no errors occur while resynchronizing a row, the
corresponding element of *prgRowStatus is set to DBROWSTATUS_S_OK. If
the method fails while resynchronizing a row, the corresponding element
is set as specified in DB_S_ERRORSOCCURRED. If prgRowStatus is a null
pointer, no row status values are returned.
The rowset allocates memory for the row status values and returns the
address to this memory; the client releases this memory with
IMalloc::Free when it is no longer needed. This argument is ignored if
pcRowsResynched is a null pointer. If *pcRowsResynched is zero on output
or the method fails, the provider does not allocate any memory and
ensures that *prgRowStatus is a null pointer on output.
S_OK
The method succeeded. All rows were successfully resynchronized.
The following value can be returned in *prgRowStatus:
* The row was successfully resynchronized. The corresponding
element of *prgRowStatus contains DBROWSTATUS_S_OK.
An error occurred while resynchronizing a row, but at least one row was
successfully resynchronized. Successes can occur for the reason listed
under S_OK. The following errors can occur:
* An element of rghRows was invalid or referred to a row that this
thread does not have access to. The corresponding element of
*prgRowStatus contains DBROWSTATUS_E_INVALID.
* Resynchronizing a row was canceled during notification. The row was
not resynchronized and the corresponding element of *prgRowStatus
contains DBROWSTATUS_E_CANCELED.
* An element of rghRows referred to a row for which a deletion had
been transmitted to the data source. The corresponding element of
*prgRowStatus contains DBROWSTATUS_E_DELETED.
* The row was not resynchronized due to reaching a limit on the
server, such as a query execution timing out. The error in the
corresponding element of *prgRowStatus contains
DBROWSTATUS_E_LIMITREACHED.
* An element of rghRows referred to a row on which a storage object
was open. The corresponding element of *prgRowStatus contains
DBROWSTATUS_E_OBJECTOPEN.
* An element of rghRows referred to a pending insert row. The
corresponding element of *prgRowStatus contains
DBROWSTATUS_E_PENDINGINSERT.
* DBPROP_STRONGIDENTITY was VARIANT_FALSE and an element of rghRows
referred to a row for which an insertion had been transmitted to
the data source. The row was not resynchronized and the
corresponding element of *prgRowStatus contains
DBROWSTATUS_E_NEWLYINSERTED.
A provider-specific error occurred.
cRows was not zero and rghRows was a null pointer. pcRowsResynched was
not a null pointer and prghRowsResynched was a null pointer.
ITransaction::Commit or ITransaction::Abort was called and the object is
in a zombie state.
Errors occurred while resynchronizing all of the rows. Errors can occur
for the reasons listed under DB_S_ERRORSOCCURRED.
The provider called a method from IRowsetNotify in the consumer and the
method has not yet returned.
The consumer did not have sufficient permission to resynchronize the
rows.
ResynchRows refreshes the values in the rowset's copy of each of the specified rows with the currently visible contents of the underlying row. Changes made to the row by the current transaction are always visible to ResynchRows, including changes made by other rowsets in the same transaction. Whether changes made by other transactions are visible to ResynchRows depends on the isolation level of the current transaction.
If a specified row has been deleted from the data source and this deletion is visible, ResynchRows returns DBROWSTATUS_E_DELETED in the error status array for the row and the row is treated as a deleted row.
Any changes transmitted to the data source are not lost; they will be committed or aborted when the transaction is committed or aborted. All pending changes are lost because they exist only in the rowset's copy of the row and ResynchRows overwrites the contents of this copy. The pending change status is removed from the row.
Additional query words: kbDatabase kbOLEDB kbSDKDataAc
Version : WINDOWS:2.0
Platform : WINDOWS
Issue type : kbinfoLast Reviewed: September 2, 1998