29.1 Comments/Troubleshooting No reference is maintained between the DataSet , the DataAdapter , and the Connection . After the DataAdapter retrieves data from a data source into a DataSet , the DataSet has no information about the connection, database, tables, columns , or any other details about the source of the data. Because the DataAdapter is a connected class, each .NET data provider implements its own DataAdapter , with a similar interface and function to other DataAdapter classes but in its own unique namespace. The DataAdapter class namespaces for several ADO.NET data providers are listed in Table 29-1. Table 29-1. Provider-specific DataAdapter classes | Class | Data source | | System.Data.SqlClient.SqlDataAdapter | SQL Server | | System.Data.OleDb.OleDbDataAdapter | OLE DB provider | | Microsoft.Data.Odbc.OdbcDataAdapter | ODBC driver | | System.Data.OracleClient.OracleDataAdapter | Oracle | The commonly used public properties of the DataAdapter class are listed in Table 29-2. Table 29-2. DataAdapter properties | Property | Description | | AcceptChangesDuringFill | Gets or sets a value indicating whether the row is committed when added to a table using the Fill( ) method. | | ContinueUpdateOnError | Gets or sets a value indicating whether the DataAdapter should raise an exception and stop processing remaining updates when an error is encountered . | | DeleteCommand | Gets or sets the command, either a SQL statement or a stored procedure, that deletes the DataSet records marked for deletion from the data source when using the Update( ) method. | | InsertCommand | Gets or sets the command, either a SQL statement or a stored procedure, that inserts new DataSet records into the data source when using the Update( ) method. | | MissingMappingAction | Specifies the action to take when columns or tables in the incoming data from the data source don't have matching columns or tables in the DataSet . | | MissingSchemaAction | Specifies the action to take when the schema of the data source doesn't match the DataSet schema. | | SelectCommand | Gets or sets the command, either a SQL statement or a stored procedure, that selects records from the data source when using the Fill( ) method. | | UpdateCommand | Gets or sets the command, either a SQL statement or a stored procedure, that updates modified Dataset records in the data source when using the Update( ) method. | The commonly used public collections of the DataAdapter class are listed in Table 29-3. Table 29-3. DataAdapter collections | Collection | Description | | TableMappings | Accesses the DataTableMappingCollection , which contains table and column name mapping information for reconciling the disconnected data with the data source, as a collection of DataTableMapping objects. | The commonly used public methods of the DataAdapter class are listed in Table 29-4. Table 29-4. DataAdapter methods | Method | Description | | Fill( ) | Adds new rows or refreshes rows in the DataSet with data from the data source. | | FillSchema( ) | Adds an empty table to the DataSet and configures its schema to match the data source. | | GetFillParameters( ) | Returns an array of parameter objects for the SelectCommand . | | Update( ) | Submits changes in the DataSet to the data source for reconciliation. | The commonly used public events of the DataAdapter class are listed in Table 29-5. Table 29-5. DataAdapter events | Event | Description | | FillError | Raised when an error is encountered during a Fill( ) operation. | | RowUpdating | Raised before the command to reconcile a DataSet row with the data source row has been executed. | | RowUpdated | Raised after the command to reconcile a DataSet row with the data source row has been executed. | The DataAdapter class inherits from Component and implements the IDataAdapter interface. Public static members of this class are safe for multithreaded operations; instance members aren't guaranteed to be thread-safe. |