CompareBookmarks Method (ADO)
Compares two bookmarks and returns an indication of their relative values.
Returns a CompareEnum value that indicates the relative row position of two records represented by their bookmarks.
The bookmarks must apply to the same Recordset object, or a Recordset object and its clone. You cannot reliably compare bookmarks from different Recordset objects, even if they were created from the same source or command. Nor can you compare bookmarks for a Recordset object whose underlying provider does not support comparisons.
A bookmark uniquely identifies a row in a Recordset object. Use the Bookmark property of the current row to obtain its bookmark.
Because the data type of a bookmark is specific to each provider, ADO exposes it as a Variant. For example, SQL Server bookmarks are of type DBTYPE_R8 (Double). ADO would expose this type as a Variant with a subtype of Double.
When comparing bookmarks, ADO does not attempt any type of coercion. The values are simply passed to the provider where the comparison occurs. If the bookmarks passed to the CompareBookmarks method are stored in variables of differing types, it can generate the following type mismatch error: "Arguments are of the wrong type, are out of the acceptable range, or are in conflict with each other."
A bookmark that is not valid or incorrectly formed will cause an error.