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

# TBooleanField

[Properties (by Name)] [Methods (by Name)] [Events (by Name)]

Boolean field class type

## Declaration

Source position: db.pas line 657

`type TBooleanField = class(TField)`
`protected`
`function GetAsBoolean; override;`
`function GetAsString; override;`
`function GetAsVariant; override;`
`function GetAsInteger; override;`
`function GetDataSize; override;`
`function GetDefaultWidth; override;`
`procedure SetAsBoolean(); override;`
`procedure SetAsString(); override;`
`procedure SetAsInteger(); override;`
`procedure SetVarValue(); override;`
`public`
`constructor Create(); override;` |  | Create a new instance of the TBooleanField class.
`property Value: Boolean; [rw]` |  | Value of the field as a boolean value
`published`
`property DisplayValues: String; [rw]` |  | Textual representation of the true and false values
`end;`

## Inheritance

`TBooleanField` |  | Boolean field class type
`TField` |  | Provide access to the contents of a single field in a record
`TComponent,IUnknown,IInterfaceComponentReference`
`TPersistent`
`TObject`

## Description

TBooleanField is the field class used by TDataset whenever it needs to manage boolean data (TField.DataType equals ftBoolean). It overrides some properties and methods of TField to be able to work with boolean data.

It should never be necessary to create an instance of TBooleanField manually, a field of this class will be instantiated automatically for each boolean field when a dataset is opened.

## See also

TDataset |  | Base class for records-based data-access
TField |  | Provide access to the contents of a single field in a record

The latest version of this document can be found at lazarus-ccr.sourceforge.net .