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ftTypedBinary

ftTypedBinary = 21

Example​

function IsProviderTypedBinary(Field: TField): Boolean;
begin
  Result := Field.DataType = ftTypedBinary;
end;

Usage​

ftTypedBinary identifies provider-defined typed binary large-object data whose representation is not described by the enum itself.

Additional Technical Info​

ftTypedBinary is declaration ordinal 21 of TFieldType. It marks binary large-object data with a type understood by the originating dataset/provider. It does not name that type or define a portable serialization.

The installed RTL maps the member to TBlobField and treats it as base ftBlob for compatibility. A subtle RTL behavior applies when assigning an IStreamPersist value: TBlobField.LoadFromStreamPersist prepends Delphi's TGraphicHeader for ftTypedBinary regardless of the GraphicHeader property because of the current condition's grouping. Raw LoadFromStream does not add that wrapper. Code using the two assignment paths can therefore store different byte sequences.

Do not infer an image, OLE object or other format from this enum. Establish the provider type and whether the stored value contains a Delphi header before decoding or exporting it. Generic SaveToStream copies stored bytes; the persistent-object path can recognise and skip a valid header. Whole-value byte access has memory proportional to payload size.

For portable integrations, prefer an explicit schema/content-type marker plus ftBlob. Treat unknown typed binary as untrusted opaque content.

The example only inspects metadata and was source-reviewed; no typed-object load, blob, stream, dataset, database, runtime or image-function test ran.

External references

Created 2026-07-15