Used to obtain a stream for reading data from or writing data to a BLOB field, specified by the Field parameter.
function CreateBlobStream(Field: TField; Mode: TBlobStreamMode): TStream; override;
Call the CreateBlobStream method to obtain a stream for reading data from or writing data to a BLOB field, specified by the Field parameter. It must be a TBlobField component. You can specify whether the stream will be used for reading, writing, or updating the contents of the field with the Mode parameter.