我想在C#中使用mdb query在列之间放置一列

using System;
using System.Data.OleDb;

namespace MDBQueryExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=your_database_path.mdb";
            
            // 创建连接对象
            using (OleDbConnection connection = new OleDbConnection(connectionString))
            {
                // 打开数据库连接
                connection.Open();

                string query = "SELECT Column1, Column2, Column3, IIF(Column1 > Column2, Column1, Column2) AS NewColumn FROM TableName";

                // 创建查询命令对象
                using (OleDbCommand command = new OleDbCommand(query, connection))
                {
                    // 执行查询，获取数据读取器
                    using (OleDbDataReader reader = command.ExecuteReader())
                    {
                        // 逐行读取数据
                        while (reader.Read())
                        {
                            // 获取每一列的值
                            int column1Value = reader.GetInt32(0);
                            int column2Value = reader.GetInt32(1);
                            int column3Value = reader.GetInt32(2);
                            int newColumnValue = reader.GetInt32(3);

                            // 在这里可以对获取到的值进行处理或输出
                            Console.WriteLine("Column1: {0}, Column2: {1}, Column3: {2}, NewColumn: {3}", column1Value, column2Value, column3Value, newColumnValue);
                        }
                    }
                }
            }
        }
    }
}