ApiIndexChangeDirection - cDbUpdateFunctionLibrary

To set the sort direction of an index segment.

Parameters: Handle hTable, Integer iIndex, Integer iSegment Integer iDirection

Parameter	Description
hTable	The table number as referenced to by Filelist.cfg
iIndex	Number of the index
iSegment	The index segment number
iDirection	DF_ASCENDING, DF_DESCENDING

Syntax

Function ApiIndexChangeDirection Handle hTable Integer iIndex Integer iSegment Integer iDirection Returns Boolean

Call:

Get ApiIndexChangeDirection Customer.File_Number 2 2 True to bOK

Description

Use it to change an index direction to ascending or descending. Important: Applies only to the embedded database (*.dat tables)

Remarks

If DF_INDEX_SEGMENT_DIRECTION is set to DF_DESCENDING, the index segment will rank from high to low rather than the default low to high. Individual segments (columns) of an index can be designated as descending or ascending. Index segments designated descending can be very useful, but can impose certain requirements on programming. For example, when a find gt (greater than) function is executed on an index containing descending segments, the gt operates as an lt (less than).

Example

Procedure OnUpdate

Boolean bOK

Get ApiIndexChangeDirection Customers.File_Number Index.2 2 DF_ASCENDING to bOK

End_Procedure