使用多个SQL表填充DataTable，并添加一个新列以了解来自哪个表。

using System;
using System.Data;
using System.Data.SqlClient;

public class Program
{
    public static void Main()
    {
        // 创建连接字符串
        string connectionString = "YourConnectionString";

        // 创建空的DataTable对象
        DataTable dataTable = new DataTable();

        // 连接到数据库
        using (SqlConnection connection = new SqlConnection(connectionString))
        {
            // 打开数据库连接
            connection.Open();

            // 填充DataTable并添加新列
            FillDataTable(connection, dataTable);

            // 关闭数据库连接
            connection.Close();
        }

        // 打印DataTable中的数据
        PrintDataTable(dataTable);
    }

    private static void FillDataTable(SqlConnection connection, DataTable dataTable)
    {
        // 创建SQL查询语句
        string query1 = "SELECT * FROM Table1";
        string query2 = "SELECT * FROM Table2";

        // 创建DataAdapter对象
        SqlDataAdapter dataAdapter = new SqlDataAdapter();

        // 填充DataTable并添加新列
        dataAdapter.SelectCommand = new SqlCommand(query1, connection);
        dataAdapter.Fill(dataTable);
        AddSourceColumn(dataTable, "Table1");

        dataAdapter.SelectCommand = new SqlCommand(query2, connection);
        dataAdapter.Fill(dataTable);
        AddSourceColumn(dataTable, "Table2");
    }

    private static void AddSourceColumn(DataTable dataTable, string source)
    {
        // 添加新列
        DataColumn sourceColumn = new DataColumn("Source", typeof(string));
        dataTable.Columns.Add(sourceColumn);

        // 为新列赋值
        foreach (DataRow row in dataTable.Rows)
        {
            row["Source"] = source;
        }
    }

    private static void PrintDataTable(DataTable dataTable)
    {
        // 打印DataTable中的数据
        foreach (DataRow row in dataTable.Rows)
        {
            foreach (DataColumn column in dataTable.Columns)
            {
                Console.WriteLine(column.ColumnName + ": " + row[column]);
            }
            Console.WriteLine();
        }
    }
}