如何在Npgsql4.0泛型参数中访问TypedValue

using Npgsql;
using NpgsqlTypes;

public class Program
{
    public static void Main()
    {
        var connString = "Host=localhost;Username=myuser;Password=mypassword;Database=mydatabase";
        using (var conn = new NpgsqlConnection(connString))
        {
            conn.Open();

            using (var cmd = new NpgsqlCommand())
            {
                cmd.Connection = conn;
                cmd.CommandText = "SELECT * FROM mytable WHERE mycolumn = @value";
                
                // 使用泛型参数指定TypedValue的类型
                cmd.Parameters.AddWithValue("value", NpgsqlDbType.Integer, 42);
                
                using (var reader = cmd.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        // 处理查询结果
                    }
                }
            }
        }
    }
}