Generic Solution Framework to Saving History of Records Using MSSQL Server 2005 Xml Column

using System;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.ComponentModel;
using System.Collections.Generic;
using System.Collections;
using System.Data;
using System.Data.Sql;
using System.Data.SqlClient;
using System.Data.SqlTypes;

namespace ConHist
{
    public partial class frmEmployees : Form
    {
        private DataSet dsForm = null;

        public frmEmployees()
        {
            InitializeComponent();
        }

        private void frmEmployees_Load(object sender, EventArgs e)
        {

            bool ret = bindData();
            if (!ret)
            {
                this.Close();
            }
        }
        private bool bindData()
        {
            try
            {
                GlobalSettings gs = GlobalSettings.Instance;
                SqlConnection cnn = new SqlConnection(gs.ConnectionString);
                string stpName = "STP_GET_EMPLOYEES";

                SqlCommand cmd = cnn.CreateCommand();
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.CommandText = stpName;

                SqlParameter pm1 = cmd.CreateParameter();
                pm1.ParameterName = "@P_ERROR_CODE";
                pm1.Direction = ParameterDirection.InputOutput;
                pm1.DbType = DbType.Int32;
                pm1.Value = 0;
                cmd.Parameters.Add(pm1);


                SqlParameter pm2 = cmd.CreateParameter();
                pm2.ParameterName = "@P_ERROR_MESSAGE";
                pm2.Direction = ParameterDirection.InputOutput;
                pm2.DbType = DbType.String;
                pm2.Size = 512;
                pm2.Value = "";
                cmd.Parameters.Add(pm2);

                cnn.Open();
                SqlDataReader dr = cmd.ExecuteReader();
                int returnCode = -1;
                string returnMessage = "";
                bool ret = Utils.ProcessReturnParameters(cmd, ref returnCode, ref returnMessage);
                if (!ret)
                {
                    Utils.ProcessErrorMessage(returnCode, returnMessage);
                    return false;
                }

                DataSet ds = new DataSet("DS_EMPLOYEES");
                DataTable dt = new DataTable("DT_EMPLOYEES");
                dt.Load(dr);
                ds.Tables.Add(dt);
                ds.AcceptChanges();
                dsForm = new DataSet();
                dsForm = ds;
                this.dataGridView1.DataSource = dsForm.Tables[0].DefaultView;
                return true;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }
        }

        private void btnEdit_Click(object sender, EventArgs e)
        {
            if (this.dataGridView1.CurrentRow == null)
            {
                return;
            }
            if (this.dataGridView1.CurrentRow.Cells["ID"] == null)
            {
                return;
            }
            string recordToEdit = this.dataGridView1.CurrentRow.Cells["ID"].Value.ToString();
            int version = int.Parse(this.dataGridView1.CurrentRow.Cells["VERSION"].Value.ToString());
            frmEditEmployee employeeEditForm = new frmEditEmployee();
            employeeEditForm.FormMode = FormMode.EditRecord;
            employeeEditForm.ID = recordToEdit;
            employeeEditForm.Version = version;
            employeeEditForm.Text = "Edit Record";
            employeeEditForm.ShowDialog();
            bindData();
        }

        private void btnRefresh_Click(object sender, EventArgs e)
        {
            this.bindData();
        }


        private void btnAdd_Click(object sender, EventArgs e)
        {
            frmEditEmployee newEmployeeForm = new frmEditEmployee();
            newEmployeeForm.FormMode = FormMode.NewRecord;
            newEmployeeForm.ID = System.Guid.NewGuid().ToString().ToUpper();
            newEmployeeForm.Version = 0;
            newEmployeeForm.Text = "Add Record";
            newEmployeeForm.ShowDialog();
            bindData();
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            if (this.dataGridView1.CurrentRow == null)
            {
                return;
            }
            if (this.dataGridView1.CurrentRow.Cells["ID"] == null)
            {
                return;
            }
            string recordToDelete = this.dataGridView1.CurrentRow.Cells["ID"].Value.ToString();
            int version = int.Parse(this.dataGridView1.CurrentRow.Cells["VERSION"].Value.ToString());
            deleteRecord(recordToDelete, version);
            bindData();
        }
        private bool deleteRecord(string recordToDelete, int version)
        {
            try
            {
                GlobalSettings gs = GlobalSettings.Instance;
                SqlConnection cnn = new SqlConnection(gs.ConnectionString);
                string stpName = "STP_DEL_EMPLOYEE";

                SqlCommand cmd = cnn.CreateCommand();
                cmd.CommandType = CommandType.StoredProcedure;
                cmd.CommandText = stpName;

                SqlParameter pm1 = cmd.CreateParameter();
                pm1.ParameterName = "@P_ERROR_CODE";
                pm1.Direction = ParameterDirection.InputOutput;
                pm1.DbType = DbType.Int32;
                pm1.Value = 0;
                cmd.Parameters.Add(pm1);


                SqlParameter pm2 = cmd.CreateParameter();
                pm2.ParameterName = "@P_ERROR_MESSAGE";
                pm2.Direction = ParameterDirection.InputOutput;
                pm2.DbType = DbType.String;
                pm2.Size = 512;
                pm2.Value = "";
                cmd.Parameters.Add(pm2);


                SqlParameter pm3 = cmd.CreateParameter();
                pm3.ParameterName = "@P_ID";
                pm3.Direction = ParameterDirection.Input;
                pm3.DbType = DbType.String;
                pm3.Size = 64;
                pm3.Value = recordToDelete;
                cmd.Parameters.Add(pm3);

                SqlParameter pm4 = cmd.CreateParameter();
                pm4.ParameterName = "@P_VERSION";
                pm4.Direction = ParameterDirection.Input;
                pm4.DbType = DbType.Int16;
                pm4.Value = version;
                cmd.Parameters.Add(pm4);


                SqlParameter pm5 = cmd.CreateParameter();
                pm5.ParameterName = "@P_TRANSACTION_USER_ID";
                pm5.Direction = ParameterDirection.Input;
                pm5.DbType = DbType.String;
                pm5.Size = 64;
                pm5.Value = gs.UserId;
                cmd.Parameters.Add(pm5);

                cnn.Open();
                cmd.ExecuteNonQuery();
                int returnCode = -1;
                string returnMessage = "";
                bool ret = Utils.ProcessReturnParameters(cmd, ref returnCode, ref returnMessage);
                if (!ret)
                {
                    Utils.ProcessErrorMessage(returnCode, returnMessage);
                    return false;
                }
                return true;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }
        }

        private void btnShowCurrentHistory_Click(object sender, EventArgs e)
        {
            if (this.dataGridView1.CurrentRow == null)
            {
                return;
            }
            if (this.dataGridView1.CurrentRow.Cells["ID"] == null)
            {
                return;
            }
            string specificRecord = this.dataGridView1.CurrentRow.Cells["ID"].Value.ToString();

            frmHistory history = new frmHistory();
            history.RelatedTable = "EMPLOYEES";
            history.SpecificRecordId = specificRecord;
            history.ShowDialog();
        }

        private void btnShowHistory_Click(object sender, EventArgs e)
        {
            frmHistory history = new frmHistory();
            history.RelatedTable = "EMPLOYEES";
            history.SpecificRecordId = "";
            history.ShowDialog();
        }
    }
}