2.2.3.11 CPMGetRowsIn

The CPMGetRowsIn message requests rows from a query. The format of the CPMGetRowsIn message that follows the header is shown in the following diagram.

_hCursor (4 bytes): A 32-bit value representing the handle from the CPMCreateQueryOut message identifying the query for which to retrieve rows.

_cRowsToTransfer (4 bytes): A 32-bit unsigned integer indicating the maximum number of rows that the client will receive in response to this message.

_cbRowWidth (4 bytes): A 32-bit unsigned integer indicating the length of a row, in bytes.

_cbSeek (4 bytes): A 32-bit unsigned integer indicating the size of the message beginning with eType.

_cbReserved (4 bytes): A 32-bit unsigned integer indicating the size, in bytes, of a CPMGetRowsOut message (without the Rows and SeekDescriptions fields). This value in this field is added to the value of the _cbSeek field, and then is to be used to calculate the offset of Rows field in the CPMGetRowsOut message.

_cbReadBuffer (4 bytes): A 32-bit unsigned integer.

Note  This field MUST be set to the maximum of the value of _cbRowWidth or 1000 times the value of _cRowsToTransfer, rounded up to the nearest 512 byte multiple. The value MUST NOT exceed 0x00004000.

_ulClientBase (4 bytes): A 32-bit unsigned integer indicating the base value to use for pointer calculations in the row buffer. If 64-bit offsets are being used, the reserved2 field of the message header is used as the upper 32-bits and _ulClientBase as the lower 32-bits of a 64-bit value. See section 2.2.3.12.

_fBwdFetch (4 bytes): A 32-bit unsigned integer indicating the order in which to fetch the rows that MUST be set to one of the following values.

Value	Meaning
0x00000000	The rows are to be fetched in forward order.
0x00000001	The rows are to be fetched in reverse order.

eType (4 bytes): A 32-bit unsigned integer that MUST contain one of the following values indicating the type of operation to perform.

Value	Meaning
0x00000000	There is no SeekDescription; the SeekDescription field is omitted.
eRowSeekNext 0x00000001	SeekDescription contains a CRowSeekNext structure.
eRowSeekAt 0x00000002	SeekDescription contains a CRowSeekAt structure.
eRowSeekAtRatio 0x00000003	SeekDescription contains a CRowSeekAtRatio structure.
eRowSeekByBookmark 0x00000004	SeekDescription contains a CRowSeekByBookmark structure.

_chapt (4 bytes): A 32-bit value representing the handle of the rowsetchapter.

SeekDescription (variable): This field MUST contain a structure of the type indicated by the eType value.

The _fBwdFetch argument affects the retrieval of rows from the results. Rows are taken from the beginning of the seek in the direction determined by the value of _fBwdFetch. In the following, a number of records have been retrieved. The figure shows how the buffer will be filled depending on the value of the _fBwdFetch. For more information about the structure of the buffer, see CPMGetRowsOut.

Notice that the _fBwdFetch argument changes the order in which records are presented for placement in the buffer but does not change the order (forward order) in which the buffer itself is filled.