以DataTable表示的最接近值

using System;
using System.Data;
using MySql.Data.MySqlClient;

public class Program
{
    public static void Main()
    {
        string connectionString = "your_connection_string";
        string query = "SELECT * FROM your_table";

        using (MySqlConnection connection = new MySqlConnection(connectionString))
        {
            connection.Open();

            MySqlCommand command = new MySqlCommand(query, connection);
            MySqlDataAdapter adapter = new MySqlDataAdapter(command);

            DataTable dataTable = new DataTable();
            adapter.Fill(dataTable);

            double targetValue = 10.5;
            double minDifference = double.MaxValue;
            int closestRowIndex = -1;

            for (int i = 0; i < dataTable.Rows.Count; i++)
            {
                double value = Convert.ToDouble(dataTable.Rows[i]["your_column"]);

                double difference = Math.Abs(targetValue - value);

                if (difference < minDifference)
                {
                    minDifference = difference;
                    closestRowIndex = i;
                }
            }

            if (closestRowIndex != -1)
            {
                DataRow closestRow = dataTable.Rows[closestRowIndex];
                Console.WriteLine("Closest value: " + closestRow["your_column"]);
                // You can access other columns in the closestRow object
            }
        }
    }
}