SSortOrder 

The SSortOrder structure defines the sort order of data in a table.

Quick Info

typedef struct _SSortOrder

{ 

     ULONG ulPropTag;

     ULONG ulOrder;

} SSortOrder, FAR *LPSSortOrder;

Members

ulPropTag

Property tag identifying the sort key column.

ulOrder

The order in which the data is to be sorted. Possible values are:

TABLE_SORT_ASCEND

The table should be sorted in ascending order.

TABLE_SORT_COMBINE

This category, as identified by the ulPropTag member, should be combined with the ulPropTag member of the previous sort order to form a sort key. This flag is only valid with categorized tables that specify multiple sort orders in a SSortOrderSet structure.

TABLE_SORT_DESCEND

The table should be sorted in descending order.

Remarks

Client applications and service providers use an SSortOrder structure for specifying a sort key for a table.

The ulPropTag member can always be set to a property tag for a column in the current view. Support for sort keys defined with available columns that are not in the current view, although valuable, depends on the implementer of the table. Some tables support these extra sort key columns; others do not. An available column is a column that is returned from IMAPITable::QueryColumns2CQT2TO when the TBL_ALL_COLUMNS flag is set.

The ulOrder member indicates both directional order and categorization information. Rows can be sorted in either an ascending or descending sequence with all NULL entries placed last. The ulOrder member can be set to TABLE_ASCEND, TABLE_DESCEND, or TABLE_SORT_COMBINE, for categorized tables.

The TABLE_SORT_COMBINE value indicates that the column specified in ulPropTag should be combined with the previous category column to form a composite category. That is, instead of categorizing on unique values of individual columns, TABLE_SORT_COMBINE allows categorization on unique values of a combination of columns. A single category could be defined, for example, to group messages received from a particular sender on a particular subject. Using TABLE_SORT_COMBINE reduces the number of category rows which are displayed.

Sorting on multivalued columns is not universally supported by all table implementations. If supported, apply the MV_FLAG using the MVI_PROP macro to the property tag in the ulPropTag member to identify the sort key as a multivalued column. Sorting on a multivalued column is based on using the individual values.

For more information about standard and categorized sorting, see Sorting and Categorization8BTQG5.

See Also