Question

this is the coe for my updation in the grid view.
when i execute it the edit command works properly but when i click update this error pops up next to my cmd.ExecuteNonQuery();
“Failed to convert parameter value from a String to a Decimal.”
please help me here.if there is another way for me to add the details into the database plz do tell me
thanks in advance. 🙂

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    string v =   System.Configuration.ConfigurationManager.ConnectionStrings["harish"].ConnectionString;
    con = new OracleConnection(v);
    con.Open();


    string query = "update leave_module1 set name=:name,desig=:desig,srno=:srno,tol=:tol,compdates=:compdates,fd=:fd,td=:td,noofdays=:nod,remarks=:remarks";
    OracleCommand cmd = new OracleCommand(query, con);
        cmd.Parameters.Add(":name", OracleType.VarChar, 50).Value = GridView1.Rows[e.RowIndex].Cells[0].Text;
        cmd.Parameters.Add(":desig", OracleType.VarChar, 30).Value = GridView1.Rows[e.RowIndex].Cells[1].Text;
        cmd.Parameters.Add(":srno", OracleType.Number, 8).Value = GridView1.Rows[e.RowIndex].Cells[2].Text;
        cmd.Parameters.Add(":tol", OracleType.VarChar, 10).Value = GridView1.Rows[e.RowIndex].Cells[3].Text;
        cmd.Parameters.Add(":compdates", OracleType.VarChar, 30).Value = GridView1.Rows[e.RowIndex].Cells[4].Text;
        cmd.Parameters.Add(":fd", OracleType.DateTime).Value = GridView1.Rows[e.RowIndex].Cells[5].Text;
        cmd.Parameters.Add(":td", OracleType.DateTime).Value = GridView1.Rows[e.RowIndex].Cells[6].Text;
        cmd.Parameters.Add(":nod", OracleType.Number, 3).Value = GridView1.Rows[e.RowIndex].Cells[7].Text;
        cmd.Parameters.Add(":remarks", OracleType.VarChar, 50).Value = GridView1.Rows[e.RowIndex].Cells[8].Text;

        cmd.ExecuteNonQuery();
        ClientScript.RegisterStartupScript(Page.GetType(), "validation", "<script language='javascript'>alert('The Data has been added');window.location='Default2.aspx';</script>;");


        cmd.Dispose();
        con.Close();    
}

Answer 1

• Do not precede the named parameter with a colon (:). The .NET Framework Data Provider for Oracle supplies the colon automatically.

• Convert parameters to relevant type before assigning to a parameter

  cmd.Parameters.Add("name", OracleType.VarChar, 50).Value = GridView1.Rows[e.RowIndex].Cells[0].Text; // this is ok 
  cmd.Parameters.Add("fd", OracleType.DateTime).Value = Convert.ToDateTime(GridView1.Rows[e.RowIndex].Cells[5].Text);
  cmd.Parameters.Add("nod", OracleType.Number, 3).Value = Convert.ToDecimal(GridView1.Rows[e.RowIndex].Cells[7].Text);
  

• Use Using block

  here is sample code

  using (var connection = new OracleConnection(connectionString))
  {
      connection.Open();
      using (var command = new OracleCommand(queryString, connection))
      {
         // add parameters here 
         command.ExecuteNonQuery();
      }
  
   }