| ADO 2.5 API Reference |  |
| ADO 2.5 API Reference | |
Appends data to a large text or binary data Field, or to a Parameter object.
object.AppendChunk Data
Use the AppendChunk method on a Field or Parameter object to fill it with long binary or character data. In situations where system memory is limited, you can use the AppendChunk method to manipulate long values in portions rather than in their entirety.
Field
If the adFldLong bit in the Attributes property of a Field object is set to true, you can use the AppendChunk method 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 you 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 you call the AppendChunk method 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 you call AppendChunk on a Field object, an error occurs.
Note The AppendChunk method does not operate on Field objects of a Record object. It does not perform any operation and will produce a run-time error.
Parameter
If the adParamLong bit in the Attributes property of a Parameter object is set to true, you can use the AppendChunk method for that parameter.
The first AppendChunk call on a Parameter object writes data to the parameter, overwriting any existing data. Subsequent AppendChunk calls on a Parameter object add to existing parameter data. An AppendChunk call that passes a null value discards all of the parameter data.
Visual Basic Example | Visual C++ Example | Visual J++ Example
Attributes Property | GetChunk Method
Applies To: Field Object | Parameter Object