Question

这是我的代码

private void button1_Click(object sender, EventArgs e)
    {
        double prate = 0;
        double srate = 0;
        double rate = 0;
        double qty = 0;
        double val = 0; bool b = false;
        List<string> item = new List<string>();
        List<string> brand = new List<string>();
        List<string> station = new List<string>();
        List<string> dealer = new List<string>();
        int m1=0, m2=0;
        for (int k = 0; k < treeView1.Nodes.Count; k++)
        {
            for (int l = 0; l < treeView1.Nodes[k].Nodes.Count; l++)
            {

                if (treeView1.Nodes[k].Nodes[l].Checked == true)
                {
                    brand.Add(treeView1.Nodes[k].Tag.ToString());
                    item.Add(treeView1.Nodes[k].Nodes[l].Tag.ToString());
                    m1++;
                }
            }
        }



        for (int i = 0; i < treeView2.Nodes.Count; i++)
        {

            for (int j = 0; j < treeView2.Nodes[i].Nodes.Count; j++)
            {
                if (treeView2.Nodes[i].Nodes[j].Checked == true)
                {
                    station.Add(treeView2.Nodes[i].Tag.ToString());
                    dealer.Add(treeView2.Nodes[i].Nodes[j].Tag.ToString());
                    m2++;
                }
            }
        }

        string[] brands; string[] items; string[] stations; string[] dealers;
        brands = brand.ToArray();
        items = item.ToArray();
        stations = station.ToArray();
        dealers = dealer.ToArray();
        SqlConnection con = new SqlConnection(Global.constr);
        con.Open();
        SqlCommand del = new SqlCommand("delete PLReport", con);
        del.ExecuteNonQuery();
        del.Dispose();
        for (int i = 0; i < m1; i++)
        {

            prate = 0;
            SqlCommand cmdr = new SqlCommand("select top 1 purchasePrice from PurchaseDetails where ItemCode='" + item[i] + "' order by doc_date Desc", con);
            SqlDataReader drr = cmdr.ExecuteReader();
            while (drr.Read())
            {
                prate = Convert.ToDouble(drr[0]);

            }
            drr.Close();
            cmdr.Dispose();
            for (int j = 0; j < m2; j++)
            {
                SqlCommand cmd33 = new SqlCommand("select slno from SalesDetails where ItemCode='" + items[i] + "' and dealer='" + dealers[j] + "' and date between '" + dateTimePicker1.Value.ToString("yyyy-MM-dd") + "' and '" + dateTimePicker2.Value.ToString("yyyy-MM-dd") + "'", con);
                SqlDataReader r33 = cmd33.ExecuteReader();
                if (!r33.HasRows)
                    continue;
                r33.Close();
                cmd33.Dispose();
                SqlCommand cmd = new SqlCommand("select sum(Qty),sum(rate) from SalesDetails where ItemCode='" + items[i] + "' and dealer='" + dealers[j] + "' and date between '" + dateTimePicker1.Value.ToString("yyyy-MM-dd") + "' and '" + dateTimePicker2.Value.ToString("yyyy-MM-dd") + "' group by ItemCode,Dealer", con);
                SqlDataReader dr = cmd.ExecuteReader();
                while (dr.Read())
                {
                    //MessageBox.Show("fgfg");
                    srate = 0;
                    b = double.TryParse(dr[1].ToString(), out srate);
                    rate = 0;
                    if (srate != 0)
                        rate = srate - prate;
                    qty = 0;
                    b = double.TryParse(dr[0].ToString(), out qty);
                    val = qty * rate;
                    if (checkBox3.Checked)//zero valued entry
                    {
                        SqlCommand cmd2 = new SqlCommand("insert PLReport values('" + stations[j] + "','" + dealers[j] + "','" + brands[i] + "','" + items[i] + "','" + val + "')", con);
                        cmd2.ExecuteNonQuery();
                        cmd2.Dispose();
                    }
                    else
                    {
                        if (val != 0)
                        {
                            SqlCommand cmd2 = new SqlCommand("insert PLReport values('" + stations[j] + "','" + dealers[j] + "','" + brands[i] + "','" + items[i] + "','" + val + "')", con);
                            cmd2.ExecuteNonQuery();
                            cmd2.Dispose();
                        }
                    }
                }
                dr.Close();
                cmd.Dispose();
            }


        }


            frmPLReport obj = new frmPLReport();
            obj.ttle = "Item Wise Profit & Loss report from " + dateTimePicker1.Value.ToString("dd/MM/yyyy") + " to " + dateTimePicker2.Value.ToString("dd/MM/yyyy");
            obj.option = 0;
            obj.ShowDialog();

        con.Close();
    }

一个'i'循环需要大约4秒才能执行，我有大约8000条记录和（项目）1000+（经销商）400条件。

这部分需要很长时间才能执行：

SqlCommand cmd = new SqlCommand("select sum(Qty),sum(rate) from SalesDetails where ItemCode='" + items[i] + "' and dealer='" + dealers[j] + "' and date between '" + dateTimePicker1.Value.ToString("yyyy-MM-dd") + "' and '" + dateTimePicker2.Value.ToString("yyyy-MM-dd") + "' group by ItemCode,Dealer", con);
SqlDataReader dr = cmd.ExecuteReader();

它太长时间如何解决问题。我的表结构中不允许索引。任何其他解决方案都会有所帮助。

Answer 1

首先，我不明白对DB的查询是否花费太长时间或其他功能或两者兼而有之。

如果你不知道，你应该从测试开始。你可以使用一个简单的DateTime.Now，看看每个部分做了多少滴答。

如果你想以更好的方式测试它，你可以像使用V4Vendetta那样使用StopWatch。你可以找到一个例子here，基本上syntext就像：

// Create new stopwatch
Stopwatch stopwatch = new Stopwatch();

// Begin timing
stopwatch.Start();

// YOUR CODE HERE

// Stop timing
stopwatch.Stop();

// Write result
Console.WriteLine("Time elapsed: {0}",
    stopwatch.Elapsed);

对于数据库访问是一个花费太长时间我可以建议你不要调用太多的SQL查询。我看到你正在调用for循环：

“从SalesDetails中选择slno ......”

可能更好地获取所有表并使用linq。这样你可以节省大量的数据库调用。同样适用于其他数据库查询，我认为我们最多可以使用3-5个数据库调用。

我的代码在执行时花了太长时间

1 个答案: