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

# TGuidField

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

Field class for native variant data

## Declaration

Source position: db.pas line 900

`type TGuidField = class(TStringField)`
`class procedure CheckTypeSize(); override;`
`protected`
`function GetDefaultWidth; override;`
`function GetAsGuid;`
`procedure SetAsGuid();`
`public`
`constructor Create(); override;` |  | Create a new instance of the TGUIDField class
`property AsGuid: TGUID; [rw]` |  | Field content as a GUID value
`end;`

## Inheritance

`TGuidField` |  | Field class for native variant data
`TStringField` |  | Field class to handle ansistring fields
`TField` |  | Provide access to the contents of a single field in a record
`TComponent,IUnknown,IInterfaceComponentReference`
`TPersistent`
`TObject`

## Description

TGUIDField is the class used when a dataset must manage native variant-typed data. (TField.DataType equals ftGUID). It initializes some of the properties of the TField class and overrides some of its methods to be able to work with variant data. It also adds a method to retrieve the field value as a native TGUID type.

It should never be necessary to create an instance of TGUIDField manually, a field of this class will be instantiated automatically for each GUID 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
TGuidField.AsGuid |  | Field content as a GUID value

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