DataView.ToTable Method (String, Boolean, String[])
Namespace: System.Data
Assembly: System.Data (in System.Data.dll)
Parameters
- tableName
- Type: System.String
The name of the returned DataTable.
- distinct
- Type: System.Boolean
If true, the returned DataTable contains rows that have distinct values for all its columns. The default value is false.
- columnNames
- Type: System.String[]
A string array that contains a list of the column names to be included in the returned DataTable. The DataTable contains the specified columns in the order they appear within this array.
Return Value
Type: System.Data.DataTableA new DataTable instance that contains the requested rows and columns.
The following console application example creates a DataTable, fills the DataTable with data, sorts the DataView, and finally creates a DataTable with a new name that contains just two columns, limited to rows in which all values are unique.
private static void DemonstrateDataView() { // Create a DataTable with three columns. DataTable table = new DataTable("NewTable"); Console.WriteLine("Original table name: " + table.TableName); DataColumn column = new DataColumn("ID", typeof(System.Int32)); table.Columns.Add(column); column = new DataColumn("Category", typeof(System.String)); table.Columns.Add(column); column = new DataColumn("Product", typeof(System.String)); table.Columns.Add(column); column = new DataColumn("QuantityInStock", typeof(System.Int32)); table.Columns.Add(column); // Add some items. DataRow row = table.NewRow(); row.ItemArray = new object[] { 1, "Fruit", "Apple", 14 }; table.Rows.Add(row); row = table.NewRow(); row.ItemArray = new object[] { 2, "Fruit", "Orange", 27 }; table.Rows.Add(row); row = table.NewRow(); row.ItemArray = new object[] { 3, "Bread", "Muffin", 23 }; table.Rows.Add(row); row = table.NewRow(); row.ItemArray = new object[] { 4, "Fish", "Salmon", 12 }; table.Rows.Add(row); row = table.NewRow(); row.ItemArray = new object[] { 5, "Fish", "Salmon", 15 }; table.Rows.Add(row); row = table.NewRow(); row.ItemArray = new object[] { 6, "Bread", "Croissant", 23}; table.Rows.Add(row); // Mark all rows as "accepted". Not required // for this particular example. table.AcceptChanges(); // Print current table values. PrintTableOrView(table, "Current Values in Table"); DataView view = new DataView(table); view.Sort = "Category"; PrintTableOrView(view, "Current Values in View"); DataTable newTable = view.ToTable("UniqueData", true, "Category", "QuantityInStock"); PrintTableOrView(newTable, "Table created from sorted DataView"); Console.WriteLine("New table name: " + newTable.TableName); Console.WriteLine("Press any key to continue."); Console.ReadKey(); } private static void PrintTableOrView(DataView dv, string label) { System.IO.StringWriter sw; string output; DataTable table = dv.Table; Console.WriteLine(label); // Loop through each row in the view. foreach (DataRowView rowView in dv) { sw = new System.IO.StringWriter(); // Loop through each column. foreach (DataColumn col in table.Columns) { // Output the value of each column's data. sw.Write(rowView[col.ColumnName].ToString() + ", "); } output = sw.ToString(); // Trim off the trailing ", ", so the output looks correct. if (output.Length > 2) { output = output.Substring(0, output.Length - 2); } // Display the row in the console window. Console.WriteLine(output); } Console.WriteLine(); } private static void PrintTableOrView(DataTable table, string label) { System.IO.StringWriter sw; string output; Console.WriteLine(label); // Loop through each row in the table. foreach (DataRow row in table.Rows) { sw = new System.IO.StringWriter(); // Loop through each column. foreach (DataColumn col in table.Columns) { // Output the value of each column's data. sw.Write(row[col].ToString() + ", "); } output = sw.ToString(); // Trim off the trailing ", ", so the output looks correct. if (output.Length > 2) { output = output.Substring(0, output.Length - 2); } // Display the row in the console window. Console.WriteLine(output); } // Console.WriteLine(); }
The example displays the following output in the console window:
Original table name: NewTable Current Values in Table 1, Fruit, Apple, 14 2, Fruit, Orange, 27 3, Bread, Muffin, 23 4, Fish, Salmon, 12 5, Fish, Salmon, 15 6, Bread, Croissant, 23 Current Values in View 3, Bread, Muffin, 23 6, Bread, Croissant, 23 4, Fish, Salmon, 12 5, Fish, Salmon, 15 1, Fruit, Apple, 14 2, Fruit, Orange, 27 Table created from sorted DataView Bread, 23 Fish, 12 Fish, 15 Fruit, 14 Fruit, 27 New table name: UniqueData
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.