The AppendChunk method on a Field object appends data to a large text or binary data Field object.
field.AppendChunk Data
The AppendChunk method is used on a Field object to fill it with long binary or character data. In situations where system memory is limited, the AppendChunk method can be used to manipulate long values in portions rather than in their entirety.
If the adFldLong bit in the Attributes property of a Field object is set to True, the AppendChunk method can be used for that field.
The first AppendChunk call on a Field object writes data to the field, overwriting any existing data. Subsequent AppendChunk calls add to existing data. If you are appending data to one field and then set or read the value of another field in the current record, ADO assumes that you are finished appending data to the first field. If the AppendChunk method is called on the first field again, ADO interprets the call as a new AppendChunk operation and overwrites the existing data. Accessing fields in other Recordset objects (that are not clones of the first Recordset object) will not disrupt AppendChunk operations.
If there is no current record when the AppendChunk method is called on a Field object, an error occurs.