filling a dataset asynchronously

Ngày tải lên: 21/01/2014, 11:20

... Cursors.Default; } private DataSet CreateDataSet( ) { DataSet ds = new DataSet( ); // Create the Orders table. DataTable dtOrders = new DataTable(ORDERS_TABLE); DataColumnCollection ... Create and fill the DataSet counting elapsed ticks. DataSet ds = CreateDataSet( ); [ Team LiB ] Recipe 9.9 Improving Performance While Filling a DataSet Problem Given a DataSet containing ... contained DataTable objects are used, if specified. A DataAdapter is used to fill a specified DataSet with data from the Orders and Order Details tables in the Northwind database. Ten iterations...

Ngày tải lên: 14/12/2013, 18:16

Ngày tải lên: 21/01/2014, 11:20

... You can use this table [ Team LiB ] Recipe 5.3 Converting a DataReader to a DataSet Problem You need to transfer data from a DataReader to a DataSet. Solution Create a DataTable schema ... (DataColumn[])pkCols.ToArray(typeof(DataColumn)); // Add the table to the DataSet. ds.Tables.Add(dataTable); object[] aData = new object[dataTable.Columns.Count]; // Read all rows from the DataReader. ... DataReader. while(dr.Read( )) { // Read the row from the DataReader into an array. dr.GetValues(aData); // Add the row from the array to the DataTable. dataTable.Rows.Add(aData); } } }...

Ngày tải lên: 07/11/2013, 13:15

... Team LiB ] Recipe 2.2 Building a DataSet Programmatically Problem You want to build a DataSet programmatically—including adding tables, columns, primary keys, and relations—from a schema ... the DataSet identifying the tables, columns, indexes, constraints, and data relations that need to be created. 2. Create a new DataSet, naming it in the constructor. 3. Create a new DataTable, ... new DataSet( "MyDataSet"); // Build the Orders (parent) table. DataTable parentTable = new DataTable("Orders"); DataColumnCollection cols = parentTable.Columns; // Add...

Ngày tải lên: 14/12/2013, 18:16

... private void encryptButton_Click(object sender, System.EventArgs e) { DataSet ds = new DataSet( ); SqlDataAdapter da; // Fill the Order table and add it to the DataSet. da = new ... SchemaType.Source); da.Fill(orderTable); ds.Tables.Add(orderTable); // Fill the OrderDetails table and add it to the DataSet. da = new SqlDataAdapter("SELECT * FROM [Order Details]", ... CryptoStreamMode.Read); ds.ReadXml(cs, XmlReadMode.ReadSchema); cs.Close( ); dataGrid.DataSource = ds.DefaultViewManager; } catch(Exception ex) { dataGrid.DataSource = null; MessageBox.Show(ex.Message,...

Ngày tải lên: 14/12/2013, 18:16

... interop. While the data can be loaded into a DataSet in this way, there is no way to reconcile the changes made to the data in the DataSet with the data source underlying the ADO object. This ... DataTable dt = new DataTable("Orders"); (new OleDbDataAdapter( )).Fill(dt, rs); conn.Close( ); // Bind the default view of the dt to the grid. dataGrid.DataSource = dt.DefaultView; ... dt.DefaultView; Discussion One of the overloads of the OLE DB .NET DataAdapter.Fill( ) method accepts an ADO Recordset or Record object. The COM component that returns an ADO Recordset or Record object...

Ngày tải lên: 14/12/2013, 18:16

... Close the reader and connection. dr.Close( ); conn.Close( ); // Load the Orders data into a table in a DataSet. DataSet ds = new DataSet( ); SqlDataAdapter da = new SqlDataAdapter(sqlText, ... xmlDoc.LoadXml(adoXml); // Create a namespace manager for the XML document. XmlNamespaceManager nm = new XmlNamespaceManager(xmlDoc.NameTable); // Add ADO prefixes. nm.AddNamespace("s", ... OleDbDataAdapter oleDa = new OleDbDataAdapter( ); DataTable dt = new DataTable("Orders"); oleDa.Fill(dt, rs); // Bind the default view of the table to the grid. dataGrid.DataSource...

Ngày tải lên: 14/12/2013, 18:16

... second, and a period of one second. Update Button.Click Uses a DataAdapter to update changes made to the first DataTable back to the data source. CheckRefreshDataSet( ) This method is called ... and a timer. The sample code contains two event handlers and one method: Form.Load Sets up the sample by creating a DataTable containing the Categories table from the Northwind database. ... database. The default view of the table is bound to a data grid on the form. A second DataTable with the auto-refreshing functionality is created that also contains the Categories table from the...

Ngày tải lên: 14/12/2013, 18:16

... it again. The DataSet in this case is referred to as a disconnected DataSet as it doesn't maintain an active connection to the database. Disconnected DataSet objects act as a data cache ... time. Instead, a better approach is to connect to the database, fetch the data into a DataSet object, and then disconnect again. The user can browse the data in the DataSet and make any changes ... Configuration Wizard. Notice that this class is defined in a namespace called NorthwindDataSetTableAdapters (as are all the other TableAdapter classes for this DataSet) . The second statement...

Ngày tải lên: 15/12/2013, 00:15

... You can push these changes to the database using the following example: mySqlDataAdapter.Update(myDataSet); All your changes to myDataSet are pushed to the database as part of the transaction ... Each of the Command objects in mySqlDataAdapter will now use mySqlTransaction. Let's say you added, modified, and removed some rows from a DataTable contained in a DataSet named myDataSet. ... mySqlTransaction. Note A transaction is rolled back by default; therefore, you should always explicitly commit or roll back your transaction using Commit() or Rollback() to make it clear what...

Ngày tải lên: 24/12/2013, 01:17

... "ORDER BY CustomerID"; SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter(); mySqlDataAdapter.SelectCommand = mySqlCommand; DataSet myDataSet = new DataSet( ); mySqlConnection.Open(); ... "ORDER BY CustomerID"; SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter(); mySqlDataAdapter.SelectCommand = mySqlCommand; DataSet myDataSet = new DataSet( ); mySqlConnection.Open(); ... Chapter 16 , "Using SQL Server's XML Support." Using the WriteXml() Method Let's say you have a DataSet object named myDataSet. Assume that myDataSet has a DataTable that...

Ngày tải lên: 24/12/2013, 01:17

... [ Team LiB ] Recipe 2.1 Retrieving Hierarchical Data into a DataSet Problem You want to fill a DataSet with parent and related child data, even if the DataSet already has a schema that ... parent table, Orders, is bound to a data grid on the form. Load DataSet Button.Click Starts by clearing the data from the DataSet and refreshing the data grid. DataAdapter objects are created ... System.EventArgs e) { // Remove all data from the DataSet and refresh the grid. ds.Clear( ); dataGrid.Refresh( ); // Create parent and child data adapters. SqlDataAdapter daParent =...

Ngày tải lên: 24/12/2013, 05:15

... tables. The XML schema and data for the DataSet is written both to a file and to a text box on the form. Read Button.Click Creates a DataSet and reads in schema and data from a file containing ... Team LiB ] Recipe 8.2 Saving and Loading a DataSet from XML Problem You need to save a DataSet as an XML file and create a DataSet from an XML file. Solution Use the XmlTextWriter and ... DataTable orderTable = new DataTable(ORDERS_TABLE); da.FillSchema(orderTable, SchemaType.Source); da.Fill(orderTable); ds.Tables.Add(orderTable); // Fill the OrderDetails table and add...

Ngày tải lên: 24/12/2013, 05:15

... If the username and password check out, then the GetUserInfo method is called, passing the username once again. The first table from the returned dataset is assigned to the DataSource property ... xmlns:msdata="urn:schemas-microsoft-com:xml-msdata"> - <xs:element name="NewDataSet" msdata:IsDataSet="true"> - <xs:complexType> - <xs:choice maxOccurs="unbounded"> ... from a data table. 2. If the goal is to include all the columns in the table and accept the Password column, then when other columns are added, you will not have to touch the code because the...

Ngày tải lên: 24/12/2013, 06:17

Ngày tải lên: 21/01/2014, 07:20

Ngày tải lên: 21/01/2014, 11:20

Ngày tải lên: 21/01/2014, 11:20

Ngày tải lên: 21/01/2014, 11:20

Ngày tải lên: 21/01/2014, 12:20