处理 Access 数据库时处理缓慢

Question

从数据库读取和写入时，设备速度呈指数级下降，并且当该过程重复时，它会变得更慢。有没有办法加快处理速度？我正在用C#编写程序Windows Applications 代码运行正常，没有问题，但问题只出现在缓慢的executable。如以下代码所述，我从第一个单元格中获取学号，然后在数据库中查找是否存在该学生的记录：如果我们找到学生的记录，向导将被引导更新学生数据如果没有找到学生记录，则将新的学生记录添加到该学生table 这是重新执行时非常慢的代码：

prog1.Value = 0;
prog2.Value = 0;
prog1.Maximum = DGV1.RowCount;
string muoadNotSave = "";
prog2.Maximum = 7;
for (int i = 0; i < DGV1.RowCount; i += 5)
     {
      FlushMemory();//دالة تفريغ الذاكرة
      if (prog1.Value < DGV1.RowCount - 2)
         {
            prog1.Value += 5;
         }
         else
         {
          prog1.Value += 1;
         }
   try
        {

        if (DGV1.Rows[i].Cells[16].Value != null)
           { string name = DGV1.Rows[i].Cells[15].Value.ToString();
             int cell_no = DGV1.ColumnCount - 4;//عدد خلايا الصف
             for (int o = 0; o <= 6; o++)
                {
                 prog2.Value += 1;
                int shoabah_No = 0;
                int studenID =     
               int.Parse(DGV1.Rows[i].Cells[16].Value.ToString());
                        string ShoabahName =
               DGV1.Rows[i].Cells[cell_no].Value.ToString();
              OleDbConnection con77 = new 
              OleDbConnection(System.Configuration
             .ConfigurationManager.ConnectionStrings["acce"].ToString());
                        OleDbCommand com77 = new OleDbCommand();
                        com77.Connection = con77;
                        com77.CommandText = "SELECT * FROM Table_Shoab 
                       where shoba_name ='" + ShoabahName + "'";
                        con77.Open();
                        OleDbDataReader r77 = com77.ExecuteReader();
                        while (r77.Read())
                        {
                            shoabah_No = 
                          int.Parse(r77["shoba_id"].ToString());

                        }
                        con77.Close();

                        if (shoabah_No != 0)
                        {
             OleDbConnection con6 = new  
             OleDbConnection(System.Configuration
            .ConfigurationManager.ConnectionStrings["acce"].ToString());
                            OleDbCommand com6 = new OleDbCommand();
                            com6.Connection = con6;

                            com6.CommandText = "insert into 
                            link_stud_shobah (shoba_id,JLOS_NO) values 
                            ('" + shoabah_No + "','" + studenID + "')";
                            con6.Open();
                            com6.ExecuteNonQuery();
                            if (con6.State == ConnectionState.Open)
                                con6.Close();

                        }
                        else
                        {
                            muoadNotSave += 
                            DGV1.Rows[i].Cells[cell_no].Value.ToString()           
                            + "  " + studenID + "\n\r";
                        }


                        cell_no += -2;
                    }
                    prog2.Value = 0;



            }
                 }

                catch (Exception ex)
            {
                //MessageBox.Show(ex.ToString());
         MessageBox.Show("اما ان يكون هناك مشكلة في الاتصال او ان الطالب " 
            + " " + DGV1.Rows[i].Cells[23].Value + " " + " سبق تسجيلة ", 
                  "تنبيه");
                // MessageBox.Show("" + ex, "تنبيه");
            }
            finally
            {

            }
        }
        if (muoadNotSave != "")
        {
            MessageBox.Show("الشعب التي لم تحفظ  "+muoadNotSave, 
          "تنبيه");
        }
        else
        {           
          MessageBox.Show("تم حفظ كافة الشعب بنجاح ولله الحمد   " + 
         muoadNotSave, "تنبيه");
        }

Answer 1

您正在（嵌套）循环中创建、打开和关闭 OleDbConnection，这很昂贵。

尝试在外循环之外执行以下操作：

OleDbConnection con77 = new OleDbConnection ..
OleDbCommand com77 = new OleDbCommand();
com77.Connection = con77;
con77.Open();
..
con77.Close();

OleDbConnection con6 = new OleDbConnection ..
OleDbCommand com6 = new OleDbCommand();
com6.Connection = con6;
con6.Open();
..
con6.Close();

此外，如果两个连接相同，您只需创建一个。

不确定 FlushMemory() 的作用，但这也可能很昂贵，最好在主循环之后调用此函数，或者根本不调用。

处理 Access 数据库时处理缓慢

Slow processing when dealing with an Access database

c#

oledb

ms-access