Visual Basic: RDO Data Control
AppendChunk Method (Remote Data)
Appends data from a Variant expression to an rdoColumn object with a data type of rdTypeLONGVARBINARY or rdTypeLONGVARCHAR.
Syntax
object**!column.AppendChunk**source
The AppendChunk method syntax has these parts:
| Part | Description |
| object | An object expression that evaluates to the rdoResultset object containing the rdoColumns collection. |
| column | An object expression that evaluates to an rdoColumn object whose ChunkRequired property is set to True. |
| source | A string expression or variable containing the data you want to append to the rdoColumn object specified by column. |
Remarks
Chunk data columns are designed to store large binary (BLOB) or text values that can range in size from a few characters to over 1.2GB and are stored in the database on successive data pages. In many cases, chunk data cannot be managed with a single operation, so you must use the chunk methods to save and write data. If the ChunkRequired property is True for a column, you should use the AppendChunk method to manipulate column data. However, if there is sufficient internal memory available, RDO might be able to carry out the operation without use of the AppendChunk method. In other words, you might be able to simply assign a value to a BLOB column.
Use the AppendChunk method to write successive blocks of data to the database column and GetChunk to extract data from the database column. Certain operations (copying, for example) involve temporary strings. If string space is limited, you may need to work with smaller segments of a chunk column instead of the entire column.
Use the BindThreshold property to specify the largest column size that will be automatically bound.
Use the ColumnSize property to determine the number of bytes in a chunk column. Note that for variable-sized columns, it is not necessary to write back the same number of bytes as returned by the ColumnSize property as ColumnSize reflects the size of the column before changes are made.
If there is no current row when you use AppendChunk, a trappable error occurs.
Note The initial AppendChunk (after the first Edit method), even if the row already contains data, replaces existing column data. Subsequent AppendChunk calls within a single Edit session appends data to existing column data.