TAdsTable.AdsEvalAOF

Advantage TDataSet Descendant

Evaluate a filter expression to determine its optimization level.

Syntax

type TAdsAOFOptimizeLevel = ( olFULL, olPART, olNONE );

function AdsEvalAOF ( strFilter : String ): TAdsEvalAOF;

Parameter

strFilter

Filter expression to evaluate to determine optimization level.

Description

AdsEvalAOF can be used to determine the optimization level of a potential filter expression. It performs the same parsing as AdsSetAOF but does not actually build the filter.

For more information, see Advantage Optimized Filters.

Example

AdsTable1.Exclusive := TRUE;

AdsTable1.Active := TRUE;

AdsTable1.AdsCreateIndex( '', 'Tag1', 'LastName', '', '', [] );

eLevel := AdsTable1.AdsEvalAOF( 'LastName = "S" .AND. EMPID > 50' );

{ eLevel equals olPart because EMPID is not indexed }

AdsTable1.AdsSetAOF( 'LastName = "S" .AND. EMPID > 50' );

eLevel := AdsTable1.AdsGetAOFOptLevel( strNonOptimizied );