TBlobField¶

Base class for BLOB field data.

Declaration¶

Source position: db.pas line 1075

type

  TBlobField = class(TField)
  public
    constructor Create;
    procedure Clear;
    class function IsBlob : Boolean;
    procedure LoadFromFile;
    procedure LoadFromStream;
    procedure SaveToFile;
    procedure SaveToStream;
    procedure SetFieldType;
    property BlobSize: LongInt; {r}
    property Modified: Boolean; {rw}
    property Value: string; {rw}
    property Transliterate: Boolean; {rw}
  published
    property BlobType: TBlobType; {rwd}
    property Size; {d}
  end;

Inheritance¶

Description¶

TBLobField is the class used when a dataset must manage BLOB data. (TField.DataType equals ftBLOB). It initializes some of the properties of the TField class, and overrides some of its methods to be able to work with BLOB fields. It also serves as parent class for some specialized blob-like field types such as TMemoField, TWideMemoField or TGraphicField

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

Properties¶

Member	Visibility	Description
BlobSize read only	public	Size of the current blob.
BlobType	published	Type of blob.
Modified	public	Has the field's contents been modified.
Size read only	published	Size of the blob field.
Transliterate	public	Should the contents of the field be transliterated.
Value	public	Return the field's contents as a string.

See all Properties

Methods¶

Member	Visibility	Description
Clear	public	Clear the BLOB field's contents.
Create	public	Create a new instance of a TBlobField class.
IsBlob	public	Is the field a blob field.
LoadFromFile	public	Load the contents of the field from a file.
LoadFromStream	public	Load the field's contents from stream.
SaveToFile	public	Save field contents to a file.
SaveToStream	public	Save the field's contents to stream.
SetFieldType	public	Set field type.

See all Methods

Name	Description
TDataset	Base class for records-based data-access.
TField	Provide access to the contents of a single field in a record.
TMemoField	Base class for MEMO (text BLOB) field data.
TWideMemoField	Field class for wide MEMO (widestring text BLOB) field data.
TGraphicField	Field class for graphical BLOB field data.