Problem in ExecuteUpdateQuery

Question

  //Presentation Layer code



if (datesvalidation () == false)
  return;
  SqlDataReader dr = null;
  try
  {
  string str = "Select Companylocation,Companyname,Designation,Empid,Experience,Fromdate,Todate,Basicpay from EmpPreviousExpDetails where Empid='" + txtemployeeid.Text + "'";
  dbConnection conn = new dbConnection();
  dr = conn.SqlReaderQuery(str);
  if (dr.Read())
  {
  BOL.bolEmpPreviousExpDetails EPED = new BOL.bolEmpPreviousExpDetails();
  EPED.Companyname = txtcompanyname.Text;
  EPED.Companylocation = txtcompanylocation.Text;
  EPED.Designation = txtdesignation.Text;
  EPED.Basicpay = Convert.ToDecimal(txtbasicpay.Text);
  EPED.EmpId = txtemployeeid.Text;
  EPED.Fromdate = Convert.ToDateTime(dtpFromDate.Value);
  EPED.Todate = Convert.ToDateTime(dtpToDate.Value);
  int experience = Convert.ToInt16(txtexperience.Text);
  if (experience <= 0)
  {
  MessageBox.Show("Experience Should Be More Than Zero","Payroll",MessageBoxButtons.OK,MessageBoxIcon.Information );
  }
  else
  {
  EPED.Experience = Convert.ToString(txtexperience.Text);
  MessageBox.Show("Records Successfully Updated","Payroll",MessageBoxButtons.OK,MessageBoxIcon.Information );
  }
  EPED.Update();
  }
  else
  {
  BOL.bolEmpPreviousExpDetails EPED = new BOL.bolEmpPreviousExpDetails();
  EPED.Companyname = txtcompanyname.Text;
  EPED.Companylocation = txtcompanylocation.Text;
  EPED.Designation = txtdesignation.Text;
  EPED.Basicpay = Convert.ToDecimal(txtbasicpay.Text);
  EPED.EmpId = txtemployeeid.Text;
  EPED.Fromdate = Convert.ToDateTime(dtpFromDate.Value);
  EPED.Todate = Convert.ToDateTime(dtpToDate.Value);
  int experience = Convert.ToInt16(txtexperience.Text);
  if (experience <= 0)
  {
  MessageBox.Show("Experience Should Be More Than Zero","Payroll",MessageBoxButtons.OK,MessageBoxIcon.Information );
  }
  else
  {
  EPED.Experience = Convert.ToString(txtexperience.Text);
  MessageBox.Show("Records Successfully Saved","Payroll",MessageBoxButtons.OK,MessageBoxIcon.Information );
  }
  EPED.Insert();
  //clearPreviousDetails();
  }
  }
 
  catch (Exception ex)
  {
  MessageBox.Show(ex.Message);
  }
  finally
  {
  dr.Close();
  }


  //Data Access layer code
 
 
  public bool Update(BOL.bolEmpPreviousExpDetails obj)
    {
      dbConnection conn =new dbConnection();
  string sql = "update EmpPreviousExpDetails set Companyname=@Companyname,Companylocation=@Companylocation,Experience=@Experience,Designation=@Designation,Basicpay=@Basicpay,Fromdate=@Fromdate,Todate=@Todate where EmpId=@EmpId";
      SqlParameter[] sqlParameters = new SqlParameter[8];
      //sqlParameters[0] = new SqlParameter("@Srlno", SqlDbType.Int);
      //sqlParameters[0].Value = obj.Srlno;
  sqlParameters[0] = new SqlParameter("@EmpId", SqlDbType.VarChar);
  sqlParameters[0].Value = obj.EmpId;
      sqlParameters[1] = new SqlParameter("@Companyname", SqlDbType.VarChar);
      sqlParameters[1].Value = obj.Companyname;
      sqlParameters[2] = new SqlParameter("@Companylocation", SqlDbType.VarChar);
      sqlParameters[2].Value = obj.Companylocation;
      sqlParameters[3] = new SqlParameter("@Experience", SqlDbType.NVarChar);
      sqlParameters[3].Value = obj.Experience;
      sqlParameters[4] = new SqlParameter("@Designation", SqlDbType.VarChar);
      sqlParameters[4].Value = obj.Designation;
      sqlParameters[5] = new SqlParameter("@Basicpay", SqlDbType.Decimal);
      sqlParameters[5].Value = obj.Basicpay;
      sqlParameters[6] = new SqlParameter("@Fromdate", SqlDbType.DateTime);
      sqlParameters[6].Value = obj.Fromdate;
      sqlParameters[7] = new SqlParameter("@Todate", SqlDbType.DateTime);
      sqlParameters[7].Value = obj.Todate;
      return conn.executeUpdateQuery(sql, sqlParameters);

  }


  //Business Layer Code

  using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace PayRoll.BOL
{
  class bolEmpPreviousExpDetails
  {
    DAL.dalEmpPreviousExpDetails dalObj= new PayRoll.DAL.dalEmpPreviousExpDetails();
    private Int32 m_Srlno;
    private string m_EmpId;
    private string m_Companyname;
    private string m_Companylocation;
    private string m_Experience;
    private string m_Designation;
    private Decimal m_Basicpay;
    private DateTime m_Fromdate;
    private DateTime m_Todate;
/// <constructor>
/// Constructor bolEmpPreviousExpDetails
/// </constructor>
    public bolEmpPreviousExpDetails()
    {
    //Initialize the variable here
    }
     /// <summary>
     /// ColumnName:Srlno
     /// Data Type:int
     /// Length:0
     /// </summary>
    public Int32 Srlno
    {
      get
      {
        return m_Srlno;
      }
      set
      {
        m_Srlno = value;
      }
    }
     /// <summary>
     /// ColumnName:Empid
     /// Data Type:VarChar
     /// Length:20
     /// </summary>
    public string EmpId
    {
      get
      {
        return m_EmpId;
      }
      set
      {
        if (value.Length > 20)
        {
  throw new InvalidData("The Empid  is more length", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
        m_EmpId = value;
      }
    }
     /// <summary>
     /// ColumnName:Companyname
     /// Data Type:VarChar
     /// Length:20
     /// </summary>
    public string Companyname
    {
      get
      {
        return m_Companyname;
      }
      set
      {
  if (value =="")
  {
  throw new InvalidData("Please Enter Company Name", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
        if (value.Length > 20)
        {
  throw new InvalidData("The Companyname  is more length", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
        m_Companyname = value;
      }
    }
     /// <summary>
     /// ColumnName:Companylocation
     /// Data Type:VarChar
     /// Length:50
     /// </summary>
    public string Companylocation
    {
      get
      {
        return m_Companylocation;
      }
      set
      {
  if (value == "")
  {
  throw new InvalidData("Please Enter Company Location", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
        if (value.Length > 50)
        {
  throw new InvalidData("The Companylocation  is more length", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
        m_Companylocation = value;
      }
    }
     /// <summary>
     /// ColumnName:Experience
     /// Data Type:nVarChar
     /// Length:20
     /// </summary>
    public string Experience
    {
      get
      {
        return m_Experience;
      }
      set
      {
  if (value == "")
  {
  throw new InvalidData("Please Enter Experience", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
        m_Experience = value;
      }
    }
     /// <summary>
     /// ColumnName:Designation
     /// Data Type:VarChar
     /// Length:20
     /// </summary>
    public string Designation
    {
      get
      {
        return m_Designation;
      }
      set
      {
  if (value == "")
  {
  throw new InvalidData("Please Enter Designation", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
        if (value.Length > 20)
        {
  throw new InvalidData("The Designation  is more length", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Warning);
        }
        m_Designation = value;
      }
    }
     /// <summary>
     /// ColumnName:Basicpay
     /// Data Type:decimal
     /// Length:0
     /// </summary>
    public Decimal Basicpay
    {
      get
      {
        return m_Basicpay;
      }
      set
      {
  if (value == 0)
  {
  throw new InvalidData("Please Enter Basic Pay", "Payroll", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
        m_Basicpay = value;
      }
    }
     /// <summary>
     /// ColumnName:Fromdate
     /// Data Type:datetime
     /// Length:0
     /// </summary>
    public DateTime Fromdate
    {
      get
      {
        return m_Fromdate;
      }
      set
      {
        m_Fromdate = value;
      }
    }
     /// <summary>
     /// ColumnName:Todate
     /// Data Type:datetime
     /// Length:0
     /// </summary>
    public DateTime Todate
    {
      get
      {
        return m_Todate;
      }
      set
      {
        m_Todate = value;
      }
    }
    public bool Insert ()
    {
      dalObj.Insert(this);
      return true;
    }
  public void get()
  {
  dalObj.get(this);
  }
  public bool Update()
  {
  dalObj.Update(this);
  return true;
  }
  }
}


//dbconnection code
public bool executeUpdateQuery(String _query, SqlParameter[] sqlParameter)
  {
  SqlCommand myCommand = new SqlCommand();
  try
  {
  myCommand.Connection = openConnection();
  myCommand.CommandText = _query;
  myCommand.Parameters.AddRange(sqlParameter);
  myAdapter.UpdateCommand = myCommand;
  myCommand.ExecuteNonQuery();
  }
  catch (SqlException e)
  {
  Console.Write("Error - Connection.executeUpdateQuery - Query: " + _query + " \nException: " + e.StackTrace.ToString());
  return false;
  }
  finally
  {
  }
  return true;
  }




//Problem in ExecuteUpdateQuery so rectify the error