----------
20190517

        public static void DataTableCollectionAddRange()
        {
            // create a DataSet with two tables
            DataSet dataSet = new DataSet();

            // create Customer table
            DataTable customersTable = new DataTable("Customers");
            customersTable.Columns.Add("customerId", typeof(int)).AutoIncrement = true;
            customersTable.Columns.Add("name", typeof(string));
            customersTable.PrimaryKey = new DataColumn[] { customersTable.Columns["customerId"] };

            // create Orders table
            DataTable ordersTable = new DataTable("Orders");
            ordersTable.Columns.Add("orderId", typeof(int)).AutoIncrement = true;
            ordersTable.Columns.Add("customerId", typeof(int));
            ordersTable.Columns.Add("amount", typeof(double));
            ordersTable.PrimaryKey = new DataColumn[] { ordersTable.Columns["orderId"] };

            dataSet.Tables.AddRange(new DataTable[] { customersTable, ordersTable });

            // print the tables and their columns
            foreach (DataTable table in dataSet.Tables)
            {
                Console.WriteLine(table.TableName);
                foreach (DataColumn column in table.Columns)
                {
                    Console.Write("{0}\table", column.ColumnName);
                }
                Console.WriteLine();
            }
        }

----------
20190517 before


The following example creates two DataTable objects and one DataRelation object, and adds the new objects to a DataSet.The tables are then displayed in a DataGridView control.

// Put the next line into the Declarations section.
private System.Data.DataSet dataSet;

private void MakeDataTables()
{
    // Run all of the functions. 
    MakeParentTable();
    MakeChildTable();
    MakeDataRelation();
    BindToDataGrid();
}

private void MakeParentTable()
{
    // Create a new DataTable.
    System.Data.DataTable table = new DataTable("ParentTable");
    // Declare variables for DataColumn and DataRow objects.
    DataColumn column;
    DataRow row;

    // Create new DataColumn, set DataType, 
    // ColumnName and add to DataTable.    
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.Int32");
    column.ColumnName = "id";
    column.ReadOnly = true;
    column.Unique = true;
    // Add the Column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType = System.Type.GetType("System.String");
    column.ColumnName = "ParentItem";
    column.AutoIncrement = false;
    column.Caption = "ParentItem";
    column.ReadOnly = false;
    column.Unique = false;
    // Add the column to the table.
    table.Columns.Add(column);

    // Make the ID column the primary key column.
    DataColumn[] PrimaryKeyColumns = new DataColumn[1];
    PrimaryKeyColumns[0] = table.Columns["id"];
    table.PrimaryKey = PrimaryKeyColumns;

    // Instantiate the DataSet variable.
    dataSet = new DataSet();
    // Add the new DataTable to the DataSet.
    dataSet.Tables.Add(table);

    // Create three new DataRow objects and add 
    // them to the DataTable
    for (int i = 0; i<= 2; i++)
    {
        row = table.NewRow();
        row["id"] = i;
        row["ParentItem"] = "ParentItem " + i;
        table.Rows.Add(row);
    }
}

private void MakeChildTable()
{
    // Create a new DataTable.
    DataTable table = new DataTable("childTable");
    DataColumn column;
    DataRow row;

    // Create first column and add to the DataTable.
    column = new DataColumn();
    column.DataType= System.Type.GetType("System.Int32");
    column.ColumnName = "ChildID";
    column.AutoIncrement = true;
    column.Caption = "ID";
    column.ReadOnly = true;
    column.Unique = true;

    // Add the column to the DataColumnCollection.
    table.Columns.Add(column);

    // Create second column.
    column = new DataColumn();
    column.DataType= System.Type.GetType("System.String");
    column.ColumnName = "ChildItem";
    column.AutoIncrement = false;
    column.Caption = "ChildItem";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    // Create third column.
    column = new DataColumn();
    column.DataType= System.Type.GetType("System.Int32");
    column.ColumnName = "ParentID";
    column.AutoIncrement = false;
    column.Caption = "ParentID";
    column.ReadOnly = false;
    column.Unique = false;
    table.Columns.Add(column);

    dataSet.Tables.Add(table);

    // Create three sets of DataRow objects, 
    // five rows each, and add to DataTable.
    for(int i = 0; i <= 4; i ++)
    {
        row = table.NewRow();
        row["childID"] = i;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 0 ;
        table.Rows.Add(row);
    }
    for(int i = 0; i <= 4; i ++)
    {
        row = table.NewRow();
        row["childID"] = i + 5;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 1 ;
        table.Rows.Add(row);
    }
    for(int i = 0; i <= 4; i ++)
    {
        row = table.NewRow();
        row["childID"] = i + 10;
        row["ChildItem"] = "Item " + i;
        row["ParentID"] = 2 ;
        table.Rows.Add(row);
    }
}

private void MakeDataRelation()
{
    // DataRelation requires two DataColumn 
    // (parent and child) and a name.
    DataColumn parentColumn = 
        dataSet.Tables["ParentTable"].Columns["id"];
    DataColumn childColumn = 
        dataSet.Tables["ChildTable"].Columns["ParentID"];
    DataRelation relation = new 
        DataRelation("parent2Child", parentColumn, childColumn);
    dataSet.Tables["ChildTable"].ParentRelations.Add(relation);
}

private void BindToDataGrid()
{
    // Instruct the DataGrid to bind to the DataSet, with the 
    // ParentTable as the topmost DataTable.
    dataGrid1.SetDataBinding(dataSet,"ParentTable");
}