The CrossTable class encapsulates a crosstab operation. Its two subclasses, ColumnCross and RowCross, represent differences in arrangements of the constructed rows. In both arrangements, the values displayed are usually aggregations, and the values in a specified database column determine the structure of the arrangement. In the ColumnCross style, the values stored in the specified column determine the column headers, whereas in the RowCross style, they determine the set of rows (one row for each value repeated for each row identifier).

The DataStream Columns array is populated (by the user or by invoking the SetCols method) with the row identifier columns. The QueryCol GroupBy attribute is automatically set for all columns in the select clause that are not part of the aggregate expression.

The query provided by the Query attribute of the SQLSelect class retrieves raw data that is adjusted for crosstab display, rather than retrieving rows that are returned directly.

The SetCols and Open methods of the DataStream class retrieve the data type of the values stored in the AcrossValues, CrossColumn, and Aggregate attributes.

The QY_CURSOR and QY_DIRECT mode distinction is meaningless for this class. For the sake of consistency, however, both are accepted and interpreted identically.

The isrepeated argument has no function but is accepted for consistency.