borland Packages Class Hierarchy dx.dataset Package
java.lang.Object +----com.borland.dx.dataset.DataSetData
Properties Methods
Implements LoadCancel, Serializable
The DataSetData
class allows you to separate the state of a DataSet
(stored by its properties)
from its data by extracting only data.
This class is serializable, and may be used to stream the
data to an output stream, or to simply be passed as an argument to a
Remote Method Invocation (RMI) method.
The DataSetData
class also allows you to load the data back into another DataSet
.
Use the DataSetData
class when developing 3-tier database applications.
While this class separates data from its properties, a few metadata-type column properties are stored within this class. These are:
DataSetData
object is populated with data.
For a custom provider and resolver example that uses the static methods of this class, see the sample project StreamableDataSets.jpr located in the DataExpress/StreamableDataSets samples folder of your JBuilder installation. The sample is documented in "Creating a distributed database application". (This sample only runs with JBuilder Enterprise.)
public static DataSetData extractDataSet(DataSet dataSet)Populates the
DataSetData
with data and non-transient data members that specify metadata information
and status bits for each row. The metadata information includes the column count, row count, column names,
data types, rowId, and whether each Column
is hidden. The status bits are used internally.
The data is organized in arrays of Column data. For example, if a data column is of type
Variant.INTEGER, an int array is used for the values of that Column
.
Any columns that don't already exist in the DataSet
are added.
sqlType
,
tableName
, and schemaName
are not contained in the DataSetData
. These
properties are not needed for editing purposes and should be extracted from the DBMS directly if needed.
public static DataSetData extractDataSetChanges(DataSet dataSet)Similar to
extractDataSet
except that it extracts the only the changes to the DataSet
(edits, inserts, and deletes) that can then be sent to the server.
public void loadDataSet(DataSet dataSet)Loads the data contained in
DataSetData
and saves it to the destination dataSet
, setting
column properties such as hidden
and rowID
. Any columns that don't already exist in the
destination dataSet
area added.