[Overview][Constants][Types][Classes][Procedures and functions][Index] | Reference for unit 'DBCtrls' (#lcl)

# TDBLookupComboBox.EmptyValue

Value stored for the lookup control when a lookup value is not available.

## Declaration

Source position: dbctrls.pp line 950

`published property TDBLookupComboBox.EmptyValue : string read GetEmptyValue write SetEmptyValue;`

## Description

EmptyValue is a String property which contains the value stored in the list of key values when no records are available in the linked lookup dataset, or when the NullValueKey shortcut is pressed.

Use EmptyValue to specify a KeyField value automatically added to the ControlItems property when the linked lookup dataset contains no records. No entry is added to Controlitems when the value in EmptyValue is an empty string (''). The value in DisplayEmpty is used for the ListField displayed in the control.

Use DisplayEmpty to specify the value displayed in the lookup control when no records are available in the linked lookup dataset, or when the NullValueKey shortcut is pressed.

## Version info

The EmptyValue and DisplayEmpty properties were added in revision 62844, and released in LCL version 2.0.8 and higher.

## See also

TDBLookup.DisplayEmpty |  | Value displayed in the lookup control when a lookup value is not available.
TDBLookup.ControlItems |  | Contains the items displayed for the lookup control.
TDBLookup.ListField |  | ListField - the name of the list field displayed for the lookup.
TDBLookup.KeyField |  | The name of the KeyField used in the lookup search.
TDBLookup.NullValueKey |  | Keyboard shortcut which causes an empty value to be assigned to each of the key fields defined for the lookup control.