Read Data from table using OleDBDataReader

Read Data from table using OleDBDataReader

protected void Page_Load(object sender, EventArgs e) { //Connection String OleDbConnection NewConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source = D:\newDtabse.mdb"); NewConnection.Open();//Connection Open //Command Query OleDbCommand cmd = new OleDbCommand("Select * from emp_tbl", NewConnection); OleDbDataReader dr = cmd.ExecuteReader(); if (dr.HasRows) { GridView1.DataSource = dr; //Using GridView to Show the data. GridView1.DataBind(); } NewConnection.Close();// Connection Close }

To read data from Access database using an OleDbCommand object

public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { //Connection String OleDbConnection NewConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source = D:\newDtabse.mdb"); OleDbCommand cmd = NewConnection.CreateCommand();//Creating Command Object cmd.CommandText = "select * from emp_tbl";//Command Text NewConnection.Open();//Connection Open OleDbDataReader dr = cmd.ExecuteReader(); if (dr.HasRows) { GridView1.DataSource = dr; //Using GridView to Show the data. GridView1.DataBind(); } NewConnection.Close();// Connection Close } }

ExecuteScaler

• ExecuteScalar() in SqlCommand Object is used for get a single value from Database after its execution.
• It executes SQL statements or Stored Procedure and returned a scalar value on first column of first row in the Result Set.
• If the Result Set is empty it will return a Null reference.
• It is very useful to use with aggregate functions like Count(*) or Sum() etc. When compare to ExecuteReader() , ExecuteScalar() uses fewer System resources.

public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { OleDbConnection NewConnection = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source = D:\newDtabse.mdb"); OleDbCommand cmd = NewConnection.CreateCommand(); cmd.CommandText = "select count(*) from emp_tbl"; NewConnection.Open(); int count =(int)cmd.ExecuteScalar(); Label1.Text = count.ToString(); } }