Inserting & Retrieving records from M.S.Access-2007 using Odbc in C#.net   Leave a comment


Objective:
          To develop a windows application for performing insert, search, update, delete operations & navigation of M.S.Access 2007 records using Odbc connection.

Introduction:
Create a table in M.S.Access 2007 file and populate it.
In our application we use ‘stud.accdb’ (M.S.Access 2007) file, which consists ‘student’ table.
(Note: ‘stud.accdb’ is placed in ‘prash_access07.zip’ along with source code)

Creating and Configuring ODBC Data Source (dsn):

Go to Start Menu -> Control Panel -> Administrative Tools -> Data Sources (ODBC)

Click on ‘Add’ button

-> Select ‘Microsoft Access Driver (*.mdb, *.accdb)’ ->click on ‘Finish’ button.

Give a name to your Data Source
Click on ‘Select’ button and select your M.S.Access 2007 file (*.accdb) -> OK -> OK

Your Data Source Name will be specified in ‘ODBC Data Source Administrator’ window
->Click on ‘OK’ button. 

Thus, your Data Source (dsn) is configured.

Design:

 Design the form as above with a DataGridView, 3 Labels, 3 TextBoxes, 10 buttons.
Introduction to Code:

As we want to use Odbc Connection include the namespace:

‘using System.Data.Odbc’

For accesing records from M.S.Access-2003 file we use ‘Jet’ driver,

But for accesing records from M.S.Access-2003 file we use ‘Ace’ driver.

In this application, we will search a record by taking input from the InputBox. For this we have to add reference to Microsoft.VisualBasic.

Adding a Reference:

Goto Project Menu ->Add Reference -> select ‘Microsoft.VisualBasic’ from .NET tab.

In order to use this we have to include the namespace:

‘using Microsoft.VisualBasic’

Odbc connection string:

Syntax:

OdbcConnection con = new OdbcConnection(“dsn=<Data Source Name>”);

Ex:
OdbcConnection con = new OdbcConnection(“dsn=myaccess07dsn “);

You just need to specify the Data Source Name(dsn) in the Connection String, no need to specify the driver details and path of the file, you dsn will take care of it.
Creating a primary key in the dataTable:

In this app. we use Find() method to search a record, which requires details of primarykey column for database tables; this is provided using statement:

adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey

But as we don’t have any primarykey column in M.S.Access table, we have to create a primary key column in datatable.
Ex:
ds.Tables[0].Constraints.Add(“pk_sno”, ds.Tables[0].Columns[0], true);
Pointing to current record in dataTable:

After searching a record, we have to get the index of that record so that we can show next and previous records when we press ‘>>'(next) and ‘<<‘(previous) buttons.
Ex:
rno= ds.Tables[0].Rows.IndexOf(drow);
————-
Code:

using System;

using System.Data;

using System.Windows.Forms;

using System.Data.Odbc;

using Microsoft.VisualBasic;

namespace prash_access07

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

        }

        OdbcConnection con;

        OdbcCommand cmd;

        OdbcDataAdapter adapter;

        DataSet ds;

        int rno;

        private void Form1_Load(object sender, EventArgs e)

        {

            con = new OdbcConnection(“dsn=myaccess07dsn”);

            //stud.accdb->access07 filename

            loaddata();

            showdata();

        }

        void loaddata()

        {

            adapter = new OdbcDataAdapter(“select * from student”, con);

            ds = new DataSet();//student-> table name in stud.accdb file

            adapter.Fill(ds, “student”);

            ds.Tables[0].Constraints.Add(“pk_sno”, ds.Tables[0].Columns[0], true);//creating primary key for Tables[0] in dataset

            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 btnFirst_Click(object sender, EventArgs e)

        {

            if (ds.Tables[0].Rows.Count > 0)

            {

                rno = 0;

                showdata();

            }

            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();

            }

            else

                MessageBox.Show(“no records”);

        }

        private void btnInsert_Click(object sender, EventArgs e)

        {

            cmd = new OdbcCommand(“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)

            {

                rno = ds.Tables[0].Rows.IndexOf(drow);

                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 OdbcCommand(“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 btnDelete_Click(object sender, EventArgs e)

        {

            cmd = new OdbcCommand(“delete from student where sno=” + textBox1.Text, con);

            con.Open();

            int n = cmd.ExecuteNonQuery();

            con.Close();

            if (n > 0)

            {

                MessageBox.Show(“Record Deleted”);

                loaddata();

            }

             else

                MessageBox.Show(“Deletion failed”);

        }

         private void btnClear_Click(object sender, EventArgs e)

        {

            textBox1.Text = textBox2.Text = textBox3.Text = “”;

        } 

        private void btnExit_Click(object sender, EventArgs e)

        {

            this.Close();

        }    

    }

}

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Posted October 13, 2010 by PrashanthChindam in c#

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