Vežba 17, Zadatak 2

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;

namespace Vezba_17_2018
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void PrikaziKategorije()
        {
            DataTable dt = Database.ExecuteQuery("SELECT COUNT(*) AS BrojKnjiga, Kategorija.Naziv AS NazivKategorije FROM Kategorija INNER JOIN Knjiga ON Kategorija.KategorijaID = Knjiga.KategorijaID GROUP BY Kategorija.Naziv");
            foreach(DataRow dr in dt.Rows)
            {
                ListViewItem item = listView1.Items.Add(dr["NazivKategorije"].ToString());
                item.Tag = dr["BrojKnjiga"];
            }
        }

        private void DrawChart()
        {
            chart.Series.Clear();
            Series series = chart.Series.Add("Broj knjiga");
            series.ChartType = SeriesChartType.Pie; // ovo promeniti za tip dijagrama
            foreach (ListViewItem item in listView1.Items)
            {
                if (item.Checked)
                {
                    DataPoint dataPoint = new DataPoint();
                    dataPoint.AxisLabel = item.Text;
                    dataPoint.YValues = new double[] { (int)item.Tag };
                    chart.Series["Broj knjiga"].Points.Add(dataPoint);
                }
            }
        }


        private void Form1_Load(object sender, EventArgs e)
        {
            PrikaziKategorije();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Close();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DrawChart();
        }
    }
}




using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.OleDb;

namespace Vezba_17_2018
{
    class Database
    {
        public static DataTable ExecuteQuery(string query)
        {
            DataTable dt = new DataTable();
            using (OleDbConnection connection = new OleDbConnection(Properties.Settings.Default.B13KolekcijaKnjigaConnectionString))
            {
                using (OleDbCommand command = new OleDbCommand(query, connection))
                {
                    connection.Open();
                    using (OleDbDataReader reader = command.ExecuteReader())
                    {
                        dt.Load(reader);
                    }
                }
            }
            return dt;
        }
    }
}