Library data save application in c#

Library data save application in c#

Develop an application that allows the user to retrieve data from a database and perform updates. The application should provide following features:

1.      A ComboBox that populates a list of items retrieved from the database for search criteria

2.      A Search button that retrieves a list of records for the item selected in the ComboBox and populates a DataGridView with these records (Master portion of the Master-Detail). Show at least 4 data columns.

3.      A set of individual fields that are filled once a row is selected in the DataGridView (Detail portion of the Master-Detail).

4.      A button to perform update to the data changed in the Detail portion.

      

  Code

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

namespace lab7

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        string query;

       

        private void Form1_Load(object sender, EventArgs e)

        {

            SqlCommand combo_pop= new SqlCommand();

            combo_pop.Connection = con; ;

            combo_pop.CommandType=CommandType.Text;

            query="select distinct author from library";

            combo_pop.CommandText= query;

          

            con.Open();

            SqlDataReader dr = combo_pop.ExecuteReader();

            while (dr.Read())

            {

                comboBox1.Items.Add((string)dr["Author"]);

            }

            dr.Close();

            con.Close();

           

  

        }

        private void search_Click(object sender, EventArgs e)

        {

            query = "select BookID,BookName,PublishDate,Price from library where Author=(@Author)";

            SqlParameter p1 = new SqlParameter("@Author", SqlDbType.NVarChar, 50, "Author");

            p1.Value = comboBox1.Text;

            SqlCommand grid_pop = new SqlCommand();

            grid_pop.Connection = con;

            grid_pop.CommandType = CommandType.Text;

            grid_pop.CommandText = query;

            grid_pop.Parameters.Add(p1);

            con.Open();

            SqlDataReader dr = grid_pop.ExecuteReader();

            DataTable table = new DataTable();

            table.Load(dr);

            dataGridView1.DataSource = table;

            con.Close();

        }

        private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)

        {

            tb2.Width = tb1.Width;

            tb1.Text = dataGridView1.CurrentRow.Cells[0].Value.ToString();

            tb2.Text = dataGridView1.CurrentRow.Cells[1].Value.ToString();

            tb3.Text = dataGridView1.CurrentRow.Cells[2].Value.ToString();

            tb4.Text = dataGridView1.CurrentRow.Cells[3].Value.ToString();

            if (tb2.Width < (TextRenderer.MeasureText(tb2.Text, tb2.Font)).Width)

                tb2.Width =(TextRenderer.MeasureText(tb2.Text, tb2.Font)).Width;

        }

     

        private void comboBox1_TextChanged(object sender, EventArgs e)

        {

          reset();

           

        }

        public void reset()

        {

            tb1.Text = "";

            tb2.Text = "";

            tb3.Text = "";

            tb4.Text = "";

            tb2.Width = tb1.Width;

            dataGridView1.DataSource = null;

            dataGridView1.Rows.Clear();

        }

        private void Update_btn_Click(object sender, EventArgs e)

        {

            SqlCommand upd_command = new SqlCommand();

            query = "update Library set BookName=@BookName, PublishDate=@PublishDate, Price=@Price where BookID=@BookID";

            upd_command.CommandType = CommandType.Text;

            upd_command.Connection = con;

            upd_command.CommandText = query;

            SqlParameter p1 = new SqlParameter("@BookID",SqlDbType.Int,4,"BookID");

            SqlParameter p2 = new SqlParameter("@BookName",SqlDbType.NVarChar,100,"BookName");

            SqlParameter p3 = new SqlParameter("@PublishDate",SqlDbType.SmallDateTime,15,"");

            SqlParameter p4 = new SqlParameter("@Price",SqlDbType.Int,4,"Price");

            p1.Value = int.Parse(tb1.Text);

            p2.Value = tb2.Text;

            p3.Value = tb3.Text;

            p4.Value = int.Parse(tb4.Text);

            upd_command.Parameters.Add(p1);

            upd_command.Parameters.Add(p2);

            upd_command.Parameters.Add(p3);

            upd_command.Parameters.Add(p4);

            con.Open();

            int rows_affected = upd_command.ExecuteNonQuery();

            con.Close();

            reset();

        }

  }

       

    }

               Screen Shot