Objective
To develop a Windows application using C#.Net to insert, search, and update records from M.S.Excel-2003 file using OleDb Connection.
Design
![Student info]()
Design the form as above with a DataGridView,3 Labels, 3 TextBoxes, and 9 buttons.
Introduction
As we want to use OleDb Connection include the namespace:'usingSystem.Data.OleDb'
For accessing records from the M.S.Excel-2003 file, we use the 'Jet' driver.
In this application, we will search a record by taking input from the InputBox. For this, we have to add a reference to Microsoft.VisualBasic.
Adding reference to Microsoft.VisualBasic
- Goto Project Menu->Add Reference -> select 'Microsoft.VisualBasic' from the .NET tab.
- To use this we have to include the namespace:'usingMicrosoft.VisualBasic'.
Creating a primary key in the data table
In this app., we use the Find() method to search a record, which requires details of the primary-key column. Database tables are provided using the statement.
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey
However since we don't have any primary key column in the M.S. Excel table, we have to create a primary key column in the data table.
Eg
ds.Tables[0].Constraints.Add("pk_sno", ds.Tables[0].Columns[0], true);
Pointing to the current record in Table
After searching for a record, we have to get the index of that record so that we can navigate the next and previous records.
Eg
rno = ds.Tables[0].Rows.IndexOf(drow);
Code
using System;
using System.Data;
using System.Data.OleDb;
using System.Windows.Forms;
using Microsoft.VisualBasic;
namespace xloledb03
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
OleDbConnection con;
OleDbCommand cmd;
OleDbDataAdapter da;
DataSet ds;
int rno = 0;
private void Form1_Load(object sender, EventArgs e)
{
con = new OleDbConnection(@"Provider=Microsoft.Jet.Oledb.4.0;data source=E:\prash\xldb.xls;Extended Properties=""Excel 8.0;HDR=Yes;"" ");
loaddata();
showdata();
}
void loaddata()
{
da = new OleDbDataAdapter("select * from [student$]", con);
ds = new DataSet();
da.Fill(ds, "student");
ds.Tables[0].Constraints.Add("pk_sno", ds.Tables[0].Columns[0], true);
dataGridView1.DataSource = ds.Tables[0];
}
void showdata()
{
textBox1.Text = ds.Tables[0].Rows[rno][0].ToString();
textBox2.Text = ds.Tables[0].Rows[rno][1].ToString();
textBox3.Text = ds.Tables[0].Rows[rno][2].ToString();
}
private void btnInsert_Click(object sender, EventArgs e)
{
cmd = new OleDbCommand("insert into [student$] values(" + textBox1.Text + ",' " + textBox2.Text + " ',' " + textBox3.Text + " ')", con);
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("record inserted");
loaddata();
}
else
MessageBox.Show("insertion failed");
}
private void btnSearch_Click(object sender, EventArgs e)
{
int n = Convert.ToInt32(Interaction.InputBox("Enter sno:", "Search", "20", 200, 200));
DataRow drow = ds.Tables[0].Rows.Find(n);
if (drow != null)
{
textBox1.Text = drow[0].ToString();
textBox2.Text = drow[1].ToString();
textBox3.Text = drow[2].ToString();
}
else
MessageBox.Show("Record not found");
}
private void btnUpdate_Click(object sender, EventArgs e)
{
cmd = new OleDbCommand(" update [student$] set sname='" + textBox2.Text + "',course='" + textBox3.Text + "' where sno=" + textBox1.Text + " ", con);
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("Record Updated");
loaddata();
}
else
MessageBox.Show("Update failed");
}
private void btnFirst_Click(object sender, EventArgs e)
{
if (ds.Tables[0].Rows.Count > 0)
{
rno = 0;
showdata();
MessageBox.Show("First Record");
}
else
MessageBox.Show("no records");
}
private void btnPrevious_Click(object sender, EventArgs e)
{
if (ds.Tables[0].Rows.Count > 0)
{
if (rno > 0)
{
rno--;
showdata();
}
else
MessageBox.Show("First Record");
}
else
MessageBox.Show("no records");
}
private void btnNext_Click(object sender, EventArgs e)
{
if (ds.Tables[0].Rows.Count > 0)
{
if (rno < ds.Tables[0].Rows.Count - 1)
{
rno++;
showdata();
}
else
MessageBox.Show("Last Record");
}
else
MessageBox.Show("no records");
}
private void btnLast_Click(object sender, EventArgs e)
{
if (ds.Tables[0].Rows.Count > 0)
{
rno = ds.Tables[0].Rows.Count - 1;
showdata();
MessageBox.Show("Last Record");
}
else
MessageBox.Show("no records");
}
private void btnClear_Click(object sender, EventArgs e)
{
textBox1.Text = textBox2.Text = textBox3.Text = "";
}
private void btnExit_Click(object sender, EventArgs e)
{
this.Close();
}
}
}
Note. The 'xldb.xls' file is provided in the xloledb03.zip file along with the source code.