/// <summary>
 /// 达梦数据库DbContext | www.csframework.com demo案例
 /// </summary>
 public class DmDbContext : DbContext
 {
     public DmDbContext(DbContextOptions<DmDbContext> options) : base(options) { }

     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
     {
         optionsBuilder.UseDm("Server=localhost;Port=5236;Uid=SYSDBA;Pwd=12345654321;");
         base.OnConfiguring(optionsBuilder);            
     }

     protected override void OnModelCreating(ModelBuilder modelBuilder)
     {
         base.OnModelCreating(modelBuilder);

         //注入测试用的模型
         modelBuilder.Entity(typeof(dt_Customer));
         modelBuilder.Entity(typeof(tb_DataSet));
     }

     /// <summary>
     /// 获取查询接口
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
     public IQueryable<T> GetQueryable<T>() where T : class
     {
         return this.Set<T>().AsQueryable<T>().AsNoTracking();
     }

 }

    //创建DbContext实例  | www.csframework.com demo案例
    var dbContext = new DmDbContext(new DbContextOptions<DmDbContext>());

    //测试查询客户表
    var q1 = dbContext.GetQueryable<dt_Customer>();
    var customer = q1.FirstOrDefault();
    Console.WriteLine(customer.CustomerCode + customer.NativeName);

    //测试新增客户
    var newCustomer = new dt_Customer
    {
        isid = Guid.NewGuid().ToString(),
        CustomerCode = "Code" + DateTime.Now.ToString("ssfff"),//秒+毫秒
        NativeName = "客户名称",
        EnglishName = "EnglishName"
    };

    dbContext.Add(newCustomer);
    dbContext.SaveChanges(); //保存数据

    //测试查询账套表
    var q2 = dbContext.GetQueryable<tb_DataSet>();
    var ds = q2.FirstOrDefault();
    Console.WriteLine(ds.DataSetID + ds.DataSetName);

    string connectionString = "Server=localhost;Port=5236;User Id=SYSDBA;Password=12345654321;";
    DmConnection connection = new DmConnection(connectionString);

    try
    {
        connection.Open();
        Console.WriteLine("数据库连接成功！");

        //这里可以执行SQL命令，例如查询或者更新操作
        DbCommand command = connection.CreateCommand();
        command.CommandText = "SELECT * FROM \"dt_Customer\"";

        DataSet ds = new DataSet();
        DbDataAdapter adapter = new DmDataAdapter();
        adapter.SelectCommand = command;
        adapter.Fill(ds);

        dataGridView1.AutoGenerateColumns = true;
        dataGridView1.DataSource = ds.Tables[0];
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
    finally
    {
        if (connection.State == ConnectionState.Open)
        {
            connection.Close();
        }
    }