[Overview][Types][Classes][Procedures and functions][Index] | Reference for unit 'BufDataset' (#fcl)

# TCustomBufDataset.IndexFieldNames

Field names included in the custom index

## Declaration

Source position: bufdataset.pas line 666

`published property TCustomBufDataset.IndexFieldNames : string read GetIndexFieldNames write SetIndexFieldNames;`

## Description

IndexFieldNames is a String property which contains a delimited list of field names used to construct the custom index for the dataset. Field names are separated by a ';' (Semicolon) delimiter. An optional directive can be included after the field name to indicate that the field should be in descending sort order in the index. For example:

    ABufDataset.IndexFieldNames := 'LASTNAME; FIRSTNAME; UPDATETS DESC';

Please note that the leading Space character before the DESC directive is required.

When reading the value in IndexFieldNames, the current index is examined to determine if any of the field names in the property also appear in the descending fields for the index. The ' DESC' directive is added to the field name to indicate the sort order used in the index.

Setting the value for the property to an empty string ('') causes the default index ('DEFAULT_ORDER') to be used as the selected index in the CurrentIndexDef property. When the new property value is not an empty string, and the dataset is Active, the BuildCustomIndex method is called to populate index storage with values for the specified field names.

## See also

TCustomBufDataset.CurrentIndexDef |  | Provides access to the index definition for the current index in the dataset
TDataset.Active |  | Is the dataset open or closed.