//deletes a supplier
        public static bool DeleteSupplier(Supplier supp)
        {
            bool success = true;//sets up return value

            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();
            string        deleteQuery = "DELETE FROM Suppliers WHERE SupplierID = @SupplierID AND SupName = @SupName";
            SqlCommand    cmd         = new SqlCommand(deleteQuery, connect);

            //inputs the parameters to check them
            cmd.Parameters.AddWithValue("@SupplierID", supp.SupID);
            cmd.Parameters.AddWithValue("@SupName", supp.SupName);

            try
            {
                connect.Open();
                int count = cmd.ExecuteNonQuery();
                if (count == 0)
                {
                    success = false;
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(success);
        }
        //adds a supplier
        public static bool AddSupplier(Supplier supp)
        {
            bool          success     = true;
            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();
            string        insertQuery = "INSERT INTO Suppliers (SupplierID, SupName) VALUES(@SupplierID, @SupName)";
            SqlCommand    cmd         = new SqlCommand(insertQuery, connect);

            //applies the values to the query
            cmd.Parameters.AddWithValue("@SupplierID", supp.SupID);
            cmd.Parameters.AddWithValue("@SupName", supp.SupName);

            try
            {
                connect.Open();
                int count = cmd.ExecuteNonQuery();
                if (count == 0)
                {
                    success = false;
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(success);
        }
        //adds an agent
        public static int AddAgent(Agent agt)
        {
            int agentID = 0;

            //Opens connection to the DB and preps insert
            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();
            string        insertQuery = "INSERT INTO Agents (AgtFirstName, AgtLastName, AgtMiddleInitial, AgtBusPhone," +
                                        "AgtEmail, AgtPosition, AgencyId) VALUES(@AgtFirstName, @AgtLastName," +
                                        "@AgtMiddleInitial, @AgtBusPhone, @AgtEmail, @AgtPosition, @AgencyId)";
            SqlCommand cmd = new SqlCommand(insertQuery, connect);

            //applies the value to the query
            cmd.Parameters.AddWithValue("@AgtFirstName", agt.AgtFirstName);
            cmd.Parameters.AddWithValue("@AgtLastName", agt.AgtLastName);
            cmd.Parameters.AddWithValue("@AgtMiddleInitial", agt.AgtMiddleInitial);
            cmd.Parameters.AddWithValue("@AgtBusPhone", agt.AgtBusPhone);
            cmd.Parameters.AddWithValue("@AgtEmail", agt.AgtEmail);
            cmd.Parameters.AddWithValue("@AgtPosition", agt.AgtPosition);
            cmd.Parameters.AddWithValue("@AgencyId", agt.AgencyID);

            try
            {
                connect.Open();
                cmd.ExecuteNonQuery();
                string     selectQuery   = "SELECT IDENT_CURRENT('Agents') FROM Agents"; //identity value
                SqlCommand selectCommand = new SqlCommand(selectQuery, connect);
                agentID     = Convert.ToInt32(selectCommand.ExecuteScalar());            //single value
                agt.AgentID = agentID;
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(agentID);
        }
        /// <summary>
        /// this method contains the logic to add the package by the user form the package form
        /// </summary>
        /// <param name="it passes the entire package object as parameter so that all information inside the object can be added"></param>
        public static void PackageAdd(Package pkgObj)
        {
            string insertStatement = "INSERT INTO Packages (PkgName,PkgStartDate,PkgEndDate,PkgDesc,PkgBasePrice,PkgAgencyCommission) " +
                                     "VALUES (@PkgName,@PkgStartDate,@PkgEndDate,@PkgDesc,@PkgBasePrice,@PkgAgencyCommission) ";

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection()) //doesn't require to close connection as USING method doest it by itself
                {
                    using (SqlCommand cmd = new SqlCommand(insertStatement, con))
                    {
                        con.Open();                             //databse connection opens
                        //    cmd.Parameters.AddWithValue("@PackageId", pkgObj.PackageId);  //auto-generated
                        cmd.Parameters.AddWithValue("@PkgName", pkgObj.PkgName);
                        cmd.Parameters.AddWithValue("@PkgBasePrice", pkgObj.PkgBasePrice);
                        if (pkgObj.PkgStartDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgStartDate", pkgObj.PkgStartDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgStartDate", DBNull.Value);
                        }

                        if (pkgObj.PkgEndDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgEndDate", pkgObj.PkgEndDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgEndDate", DBNull.Value);
                        }

                        if (pkgObj.PkgDesc != null)
                        {
                            cmd.Parameters.AddWithValue("@PkgDesc", pkgObj.PkgDesc);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgDesc", "");
                        }

                        if (pkgObj.PkgAgencyCommission.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgAgencyCommission", pkgObj.PkgAgencyCommission);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgAgencyCommission", 0);
                        }

                        cmd.ExecuteNonQuery();
                    }
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        //deletes an agent
        public static bool DeleteAgent(Agent agt)
        {
            bool success = true;

            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();
            string        deleteQuery = "DELETE FROM agents WHERE AgentId = @AgentID AND AgtFirstName = @AgtFirstName " +
                                        "AND AgtMiddleInitial = @AgtMiddleInitial AND AgtLastName = @AgtLastName AND " +
                                        "AgtBusPhone = @AgtBusPhone AND AgtEmail = @AgtEmail AND AgtPosition = @AgtPosition AND " +
                                        "AgencyId = @AgencyID";
            SqlCommand cmd = new SqlCommand(deleteQuery, connect);

            //inputs the parameters to check them
            cmd.Parameters.AddWithValue("@AgentID", agt.AgentID);
            cmd.Parameters.AddWithValue("@AgtFirstName", agt.AgtFirstName);
            cmd.Parameters.AddWithValue("@AgtMiddleInitial", agt.AgtMiddleInitial);
            cmd.Parameters.AddWithValue("@AgtLastName", agt.AgtLastName);
            cmd.Parameters.AddWithValue("@AgtBusPhone", agt.AgtBusPhone);
            cmd.Parameters.AddWithValue("@AgtEmail", agt.AgtEmail);
            cmd.Parameters.AddWithValue("@AgtPosition", agt.AgtPosition);
            cmd.Parameters.AddWithValue("@AgencyID", agt.AgencyID);

            try
            {
                connect.Open();
                int count = cmd.ExecuteNonQuery();
                if (count == 0)
                {
                    success = false;
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(success);
        }
        //Delete Product
        public static bool DeleteProduct(Product p)
        {
            bool success = true;

            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            string strSqlUpdate = "DELETE FROM Products " +
                                  "WHERE ProductId = @ProductId " +  //customer id identifies record to update
                                  "AND ProdName = @ProdName";

            SqlCommand cmd = new SqlCommand(strSqlUpdate, con);

            //set parameters for old customer dat
            cmd.Parameters.AddWithValue("@ProductId", p.ProductId);
            cmd.Parameters.AddWithValue("@ProdName", p.ProdName);

            try
            {
                con.Open();
                int rowsUpdated = cmd.ExecuteNonQuery();
                if (rowsUpdated == 0)
                {
                    success = false;                   //did not update, most likey b/c of concurreny exception event
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
            return(success);
        }
        /// <summary>
        /// below method has the logic to check if the selected package information to be deleted has any child dependency to be checked
        /// </summary>
        /// <returns>it returns the list of name of the package which is used to compare and show appropriate message to the user on the package form</returns>

        public static List <string> CheckBeforeDelete()
        {
            List <string> packageNames = new List <string>();

            string query = "SELECT PackageId,PkgName from packages Where EXISTS " +
                           "(SELECT b.packageid, p.packageid from bookings b,Packages_Products_Suppliers p where b.packageid=p.packageid)";

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(query, con))
                    {
                        con.Open();                                                            //databse connection opens
                        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); //Data reader executes the query and bring all data before closing connection to the table
                        while (dr.Read())                                                      //below block of code executes till there is data in the table
                        {
                            packageNames.Add(Convert.ToString(dr["PkgName"]));
                        }
                    }
                    return(packageNames);                         //returns the list of package
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// this method displays the related booking in the booking data grid on the Package form
        /// </summary>
        /// <param name="PackageId is passed as parameter to use it in SQL query to fetch correct records"></param>
        /// <returns>list of related bookings for the selected package</returns>


        public static List <Bookings> DisplayBookingsInGrid(int pkgId)
        {
            List <Bookings> bookingList = new List <Bookings>();

            string selectQuery = "select BookingNo,CustomerId,TripTypeId from bookings where PackageId IN (Select PackageId from packages WHERE PackageId=@pkgId) ";   //SQL query to get all fields from table

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(selectQuery, con))
                    {
                        con.Open();                                                            //databse connection opens
                        cmd.Parameters.AddWithValue("@pkgId", pkgId);                          //binding it with PkgId parameter which is passed on in an arguement

                        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); //Data reader executes the query and bring all data before closing connection to the table
                        while (dr.Read())                                                      //below block of code executes till there is data in the table
                        {
                            Bookings bkngObj = new Bookings();                                 //instantiating the object of the class booking

                            bkngObj.BookingNo  = (string)dr["BookingNo"];
                            bkngObj.CustomerId = (int)dr["CustomerId"];
                            bkngObj.TripTypeId = (string)dr["TripTypeId"];

                            bookingList.Add(bkngObj);        //adding booking items into the list
                        }
                    }
                    return(bookingList);                         //returns the list of booking
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        //grabs the suppliers
        public static List <Supplier> GetSuppliers()
        {
            //List and holder created
            List <Supplier> suppliers = new List <Supplier>();
            Supplier        supplierHolder;

            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();//defines db connection
            string        selectQuery = "SELECT SupplierID, SupName FROM Suppliers ORDER BY SupplierID";
            SqlCommand    cmd         = new SqlCommand(selectQuery, connect);

            try
            {
                connect.Open();
                SqlDataReader reader = cmd.ExecuteReader();

                //runs until all data has been read
                while (reader.Read())
                {
                    supplierHolder         = new Supplier();
                    supplierHolder.SupID   = (int)reader["SupplierID"];
                    supplierHolder.SupName = reader["SupName"].ToString();

                    suppliers.Add(supplierHolder);//adds to list
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(suppliers);//returns the list
        }
Пример #10
0
        //gets the agency table from the database
        public static List <Agency> GetAgencies()
        {
            List <Agency> agencies = new List <Agency>();
            Agency        agency;

            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();
            string        selectQuery = "SELECT AgencyId, AgncyAddress, AgncyCity, AgncyProv, AgncyPostal, " +
                                        "AgncyCountry, AgncyPhone, AgncyFax FROM Agencies";
            SqlCommand cmd = new SqlCommand(selectQuery, connect);

            try
            {
                connect.Open();
                SqlDataReader reader = cmd.ExecuteReader();

                //runs until all data has been read
                while (reader.Read())
                {
                    agency = new Agency();

                    agency.AgencyID      = (int)reader["AgencyId"];
                    agency.AgencyAddress = reader["AgncyAddress"].ToString();
                    agency.AgencyCity    = reader["AgncyCity"].ToString();
                    agency.AgencyProv    = reader["AgncyProv"].ToString();
                    agency.AgencyPostal  = reader["AgncyPostal"].ToString();
                    agency.AgencyCountry = reader["AgncyCountry"].ToString();
                    agency.AgencyFax     = reader["AgncyFax"].ToString();

                    agencies.Add(agency);//adds to list
                }
            }catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(agencies);
        }
        //updates an agent
        public static bool UpdateAgent(Agent oldAgent, Agent newAgent)
        {
            bool success = true;

            SqlConnection connect = TravelExpertsDBConn.getDbConnection();
            //only needs ID, rest checks for concurrency issues
            string updateQuery = "UPDATE Agents SET AgtFirstName = @NewAgtFirstName, " +
                                 "AgtMiddleInitial = @NewAgtMiddleInitial, " +
                                 "AgtLastName = @NewAgtLastName, " +
                                 "AgtBusPhone = @NewAgtBusPhone, " +
                                 "AgtEmail = @NewAgtEmail, " +
                                 "AgtPosition = @newAgtPosition, " +
                                 "AgencyId = @NewAgencyId " +
                                 "WHERE AgentId = @OldAgentId " +
                                 "AND AgtFirstName = @OldAgtFirstName " +
                                 "AND AgtMiddleInitial = @OldAgtMiddleInitial " +
                                 "AND AgtLastName = @OldAgtLastName " +
                                 "AND AgtBusPhone = @OldAgtBusPhone " +
                                 "AND AgtEmail = @OldAgtEmail " +
                                 "AND AgtPosition = @OldAgtPosition " +
                                 "AND AgencyId = @OldAgencyId";
            SqlCommand cmd = new SqlCommand(updateQuery, connect);

            //sets the parameters
            cmd.Parameters.AddWithValue("@NewAgtFirstName", newAgent.AgtFirstName);
            cmd.Parameters.AddWithValue("@NewAgtMiddleInitial", newAgent.AgtMiddleInitial);
            cmd.Parameters.AddWithValue("@NewAgtLastName", newAgent.AgtLastName);
            cmd.Parameters.AddWithValue("@NewAgtBusPhone", newAgent.AgtBusPhone);
            cmd.Parameters.AddWithValue("@NewAgtEmail", newAgent.AgtEmail);
            cmd.Parameters.AddWithValue("@NewAgtPosition", newAgent.AgtPosition);
            cmd.Parameters.AddWithValue("@NewAgencyId", newAgent.AgencyID);

            cmd.Parameters.AddWithValue("@OldAgentId", oldAgent.AgentID);
            cmd.Parameters.AddWithValue("@OldAgtFirstName", oldAgent.AgtFirstName);
            cmd.Parameters.AddWithValue("@OldAgtMiddleInitial", oldAgent.AgtMiddleInitial);
            cmd.Parameters.AddWithValue("@OldAgtLastName", oldAgent.AgtLastName);
            cmd.Parameters.AddWithValue("@OldAgtBusPhone", oldAgent.AgtBusPhone);
            cmd.Parameters.AddWithValue("@OldAgtEmail", oldAgent.AgtEmail);
            cmd.Parameters.AddWithValue("@OldAgtPosition", oldAgent.AgtPosition);
            cmd.Parameters.AddWithValue("@OldAgencyId", oldAgent.AgencyID);

            try
            {
                connect.Open();
                int rowsUpdated = cmd.ExecuteNonQuery();
                if (rowsUpdated == 0)
                {
                    success = false;                  //did not update, concurrency issue
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(success);
        }
Пример #12
0
        //get list of ProductSuppliers from database for a given supplier id
        public static List <ProductSupplier> GetProductSuppliersBySupplierID(int sId)
        {
            List <ProductSupplier> ps = new List <ProductSupplier>();  //empty list

            //create connection
            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            //create sql statement
            string strSqlSelect = "SELECT ProductSupplierId, ProductId, SupplierId " +
                                  "FROM Products_Suppliers " +
                                  "ORDER BY ProductSupplierId" +
                                  "WHERE SupplierId=@SupplierId";

            //create sql command
            SqlCommand cmd = new SqlCommand(strSqlSelect, con);

            cmd.Parameters.AddWithValue("@SupplierId", sId);

            //try-catch sql command execution
            try
            {
                con.Open();

                SqlDataReader dr = cmd.ExecuteReader();

                while (dr.Read())
                {
                    ProductSupplier p = new ProductSupplier();

                    p.ProductSupplierId = Convert.ToInt32(dr["ProductSupplierId"]);
                    p.ProductId         = Convert.ToInt32(dr["ProductId"]);
                    p.SupplierId        = Convert.ToInt32(dr["SupplierId"]);

                    ps.Add(p);
                }
            }
            catch (Exception ex)  //handle sql exceptions
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
            //return list
            return(ps);
        }
        //get Products
        public static List <Product> GetProducts()
        {
            List <Product> products = new List <Product>();  //empty list

            //create connection
            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            //create sql statement
            string strSqlSelect = "SELECT ProductId, ProdName FROM Products ORDER BY ProdName";



            //create sql command
            SqlCommand cmd = new SqlCommand(strSqlSelect, con);

            //try-catch sql command execution
            try
            {
                con.Open();

                SqlDataReader dr = cmd.ExecuteReader();

                while (dr.Read())
                {
                    Product p = new Product();

                    p.ProductId = Convert.ToInt32(dr["ProductId"]);
                    p.ProdName  = dr["ProdName"].ToString();

                    products.Add(p);
                }
            }
            catch (Exception ex)  //handle sql exceptions
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
            //return list
            return(products);
        }
Пример #14
0
        //Update ProductSupplier
        public static bool UpdateProductSupplier(ProductSupplier oldProductSupplier, ProductSupplier newProductSupplier)
        {
            bool success = true;

            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            string strSqlUpdate = "UPDATE Products_Suppliers " +
                                  "SET ProductId = @ProductIdNew, SupplierId = @SupplierIdNew, " +
                                  "WHERE ProductSupplierId = @ProductSupplierIdOld " +  //customer Id Identifies record to update
                                  "AND ProductId = @ProductIdOld " +
                                  "AND SupplierId = @SupplierIdOld";

            SqlCommand cmd = new SqlCommand(strSqlUpdate, con);

            //set parameters for new customer data
            cmd.Parameters.AddWithValue("@ProductIdNew", newProductSupplier.ProductId);
            cmd.Parameters.AddWithValue("@SupplierIdNew", newProductSupplier.SupplierId);

            //set parameters for old customer dat
            cmd.Parameters.AddWithValue("@ProductSupplierIdOld", oldProductSupplier.ProductSupplierId);
            cmd.Parameters.AddWithValue("@ProductIdOld", oldProductSupplier.ProductId);
            cmd.Parameters.AddWithValue("@SupplierIdOld", oldProductSupplier.SupplierId);

            try
            {
                con.Open();
                int rowsUpdated = cmd.ExecuteNonQuery();
                if (rowsUpdated == 0)
                {
                    success = false;                   //dId not update, most likey b/c of concurreny exception event
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
            return(success);
        }
Пример #15
0
        //get ProductSupplier by Id
        public static ProductSupplier getProductSupplierById(int ProductSupplierId)
        {
            ProductSupplier ps = null;  //return null if no ProductSupplier exists for Id


            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            //create sql statement
            string strSqlSelect = "SELECT ProductSupplierId, ProductId, SupplierId FROM Products_Suppliers " +
                                  "WHERE ProductSupplierId = @ProductSupplierId";

            //create sql command
            SqlCommand cmd = new SqlCommand(strSqlSelect, con);

            cmd.Parameters.AddWithValue("@ProductSupplierId", ProductSupplierId);

            try
            {
                con.Open();

                SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.SingleRow);

                if (dr.Read())
                {
                    ps = new ProductSupplier();

                    ps.ProductSupplierId = Convert.ToInt32(dr["ProductSupplierId"]);
                    ps.ProductId         = Convert.ToInt32(dr["ProductId"]);
                    ps.SupplierId        = Convert.ToInt32(dr["SupplierId"]);
                }
            }
            catch (Exception ex)  //handle sql exceptions
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }
            //return list
            return(ps);
        }
Пример #16
0
        //Add ProductSupplier
        public static int AddProductSupplier(ProductSupplier ps)
        {
            int ProductSupplierId = 0;

            //create connection
            SqlConnection con = TravelExpertsDBConn.getDbConnection();

            //create SQL statement
            string strSqlInsert = "INSERT INTO Products_Suppliers(ProductId, SupplierId)" +
                                  "VALUES(@ProductId, @SupplierId)";

            //create sql command and populate parameters
            SqlCommand cmd = new SqlCommand(strSqlInsert, con);

            cmd.Parameters.AddWithValue("@ProductId", ps.ProductId);
            cmd.Parameters.AddWithValue("@SupplierId", ps.SupplierId);

            try
            {
                con.Open();
                //execute insert statement
                cmd.ExecuteNonQuery();

                //get ProductSupplier Id of inserted record from database
                string     strSqlSelect = "SELECT IDENT_CURRENT('Products_Suppliers') FROM Products_Suppliers";
                SqlCommand cmdSelect    = new SqlCommand(strSqlSelect, con);

                ProductSupplierId = Convert.ToInt32(cmdSelect.ExecuteScalar());
            }
            catch (Exception ex)  //handle sql exceptions
            {
                throw ex;
            }
            finally
            {
                con.Close();
            }

            //return result
            return(ProductSupplierId);
        }
        public static List <Supplier> DisplaySuppliersInList(int pkgId)
        {
            List <Supplier> supplierList = new List <Supplier>(); //crating empty list
            Supplier        supplierObj  = null;                  //referencing supplier object

            string selectQuery = "SELECT s.SupplierId as 'supplier',s.SupName,ps.ProductSupplierId " +
                                 "FROM Suppliers s " +
                                 "INNER JOIN Products_Suppliers ps " +
                                 "ON s.SupplierId = ps.SupplierId " +
                                 "INNER JOIN Packages_Products_Suppliers pps " +
                                 "ON ps.ProductSupplierId = pps.ProductSupplierId " +
                                 "INNER JOIN Packages pk " +
                                 "ON pps.PackageId = pk.PackageId  WHERE pk.PackageId = @pkgId";

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(selectQuery, con))
                    {
                        con.Open();                                                            //databse connection opens
                        cmd.Parameters.AddWithValue("@pkgId", pkgId);                          //binding it with PkgId parameter which is passed on in an arguement
                        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); //Data reader executes the query and bring all data before closing connection to the table
                        while (dr.Read())                                                      //below block of code executes till there is data in the table
                        {
                            supplierObj         = new Supplier();                              //instantiating the object of the class Supplier
                            supplierObj.SupName = (string)dr["SupName"];

                            supplierList.Add(supplierObj);        //adding supplier items into the list
                        }
                    }
                    return(supplierList);                         //returns the list of suppliers
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        //grabs the agents
        public static List <Agent> GetAgents()
        {
            //list and holder created
            List <Agent> agents = new List <Agent>();
            Agent        agentHolder;

            SqlConnection connect     = TravelExpertsDBConn.getDbConnection();//defines db connection
            string        selectQuery = "SELECT AgentId, AgtFirstName, AgtMiddleInitial, AgtLastName," +
                                        "AgtBusPhone, AgtEmail, AgtPosition, AgencyId FROM agents";
            SqlCommand cmd = new SqlCommand(selectQuery, connect);

            try
            {
                connect.Open();
                SqlDataReader reader = cmd.ExecuteReader();

                //runs until all data has been read
                while (reader.Read())
                {
                    agentHolder = new Agent();

                    agentHolder.AgentID          = (int)reader["AgentId"];
                    agentHolder.AgtFirstName     = reader["AgtFirstName"].ToString();
                    agentHolder.AgtLastName      = reader["AgtLastName"].ToString();
                    agentHolder.AgtMiddleInitial = reader["AgtMiddleInitial"].ToString();
                    agentHolder.AgtBusPhone      = reader["AgtBusPhone"].ToString();
                    agentHolder.AgtEmail         = reader["AgtEmail"].ToString();
                    agentHolder.AgtPosition      = reader["AgtPosition"].ToString();
                    agentHolder.AgencyID         = (int)reader["AgencyId"];

                    agents.Add(agentHolder);//adds to list
                }
            }
            catch (Exception e) { throw e; }
            finally { connect.Close(); }

            return(agents);
        }
        /// <summary>
        /// GetPackage() method mentions the logic about getting all packages from the Packages table from TravelExpert database from SQL
        /// and the method is called at presentation layer on the Main form_load event.
        /// </summary>
        /// <returns>List of packages</returns>
        public static List <Package> DisplayPackagesInGrid()
        {
            List <Package> packageList = new List <Package>();                  //crating empty list
            Package        packageObj  = null;                                  //referencing package object

            string selectQuery = "SELECT * FROM Packages ORDER BY PkgName ASC"; //SQL query to get all fields from table

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(selectQuery, con))
                    {
                        con.Open();                                                            //databse connection opens
                        SqlDataReader dr = cmd.ExecuteReader(CommandBehavior.CloseConnection); //Data reader executes the query and bring all data before closing connection to the table
                        while (dr.Read())                                                      //below block of code executes till there is data in the table
                        {
                            packageObj              = new Package();                           //instantiating the object of the class Package
                            packageObj.PackageId    = (int)dr["PackageId"];
                            packageObj.PkgName      = (string)dr["PkgName"];
                            packageObj.PkgStartDate = dr["PkgStartDate"] == DBNull.Value ? null : (DateTime?)dr["PkgStartDate"];
                            packageObj.PkgEndDate   = dr["PkgEndDate"] == DBNull.Value ? null : (DateTime?)dr["PkgEndDate"];
                            packageObj.PkgDesc      = dr["PkgDesc"] == DBNull.Value ? null : (string)dr["PkgDesc"];
                            packageObj.PkgBasePrice = double.Parse(dr["PkgBasePrice"].ToString());

                            packageObj.PkgAgencyCommission = dr["PkgAgencyCommission"] == DBNull.Value ? Convert.ToDouble(null) : double.Parse(dr["PkgAgencyCommission"].ToString());
                            packageList.Add(packageObj);        //adding package items into the list
                        }
                    }
                    return(packageList);                         //returns the list of package
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// this below method has the logic of deleting the selected package information. it also takes care of database concurrancy
        /// </summary>
        /// <param name="the entire package object is passed as parameter as it contains all information to be deleted"></param>
        /// <returns>it returns the boolean(true/false), true if delete is successful and false if not</returns>

        public static bool PackageDelete(Package pkgObj)
        {
            bool result = true;

            string deleteStatement = "DELETE FROM Packages WHERE PackageId = @PackageId " +
                                     "AND PkgName = @PkgName " +
                                     "AND (PkgDesc = @PkgDesc OR @PkgDesc is NULL AND PkgDesc is NULL)  " +
                                     "AND (PkgStartDate = @PkgStartDate OR @PkgStartDate is NULL AND PkgStartDate is NULL) " +
                                     "AND (PkgEndDate = @PkgEndDate OR @PkgEndDate is NULL AND PkgEndDate is NULL) " +
                                     "AND PkgBasePrice = @PkgBasePrice " +
                                     "AND (PkgAgencyCommission = @PkgAgencyCommission OR @PkgAgencyCommission is NULL AND PkgAgencyCommission is NULL)";

            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(deleteStatement, con))
                    {
                        con.Open();
                        cmd.Parameters.AddWithValue("@PackageId", pkgObj.PackageId);
                        cmd.Parameters.AddWithValue("@PkgName", pkgObj.PkgName);
                        cmd.Parameters.AddWithValue("@PkgBasePrice", pkgObj.PkgBasePrice);
                        if (pkgObj.PkgStartDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgStartDate", pkgObj.PkgStartDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgStartDate", DBNull.Value);
                        }

                        if (pkgObj.PkgEndDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgEndDate", pkgObj.PkgEndDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgEndDate", DBNull.Value);
                        }

                        if (String.IsNullOrEmpty(pkgObj.PkgDesc))
                        {
                            cmd.Parameters.AddWithValue("@PkgDesc", "");
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgDesc", pkgObj.PkgDesc);
                        }

                        if (pkgObj.PkgAgencyCommission.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@PkgAgencyCommission", pkgObj.PkgAgencyCommission);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@PkgAgencyCommission", 0);
                        }



                        int count = cmd.ExecuteNonQuery();
                        if (count == 0) // optimistic concurrency violation
                        {
                            result = false;
                        }
                    }
                }
                return(result);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        /// <summary>
        /// this method contains the logic to save the updated record in the database.
        /// </summary>
        /// <param name="package"></param>
        /// <param name="here 2 parameters are passed in, 1st one is old package object which is already ther in the database
        /// and 2nd one is new package object which contains updated information from the package form"></param>
        /// <returns>it returns the boolean(true/false), true if update is successful and false if not</returns>

        public static bool PackageUpdate(Package package, Package newPackage)
        {
            bool result = true;

            string updateStatement = "UPDATE Packages SET  PkgName = @newPkgName, " +
                                     "PkgStartDate = @newPkgStartDate, " +
                                     "PkgEndDate = @newPkgEndDate, " +
                                     "PkgDesc = @newPkgDesc, " +
                                     "PkgBasePrice=@newPkgBasePrice, " +
                                     "PkgAgencyCommission = @newPkgAgencyCommission " +
                                     "WHERE PackageId = @oldPackageId ";

            //"AND PkgName = @oldPkgName " +
            //"AND PkgStartDate = @oldPkgStartDate " +
            //"AND PkgEndDate = @oldPkgEndDate " +
            //"AND PkgDesc = @oldPkgDesc " +
            //"AND PkgBasePrice=@oldPkgBasePrice " +
            //"AND PkgAgencyCommission = @oldPkgAgencyCommission";


            try
            {
                using (SqlConnection con = TravelExpertsDBConn.getDbConnection())
                {
                    using (SqlCommand cmd = new SqlCommand(updateStatement, con))
                    {
                        con.Open();
                        //cmd.Parameters.AddWithValue("@PackageId", newPackage.PackageId);
                        cmd.Parameters.AddWithValue("@newPkgName", newPackage.PkgName);
                        cmd.Parameters.AddWithValue("@newPkgBasePrice", newPackage.PkgBasePrice);
                        if (newPackage.PkgStartDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@newPkgStartDate", newPackage.PkgStartDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@newPkgStartDate", DBNull.Value);
                        }

                        if (newPackage.PkgEndDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@newPkgEndDate", newPackage.PkgEndDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@newPkgEndDate", DBNull.Value);
                        }

                        if (newPackage.PkgDesc == null)
                        {
                            cmd.Parameters.AddWithValue("@newPkgDesc", "");
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@newPkgDesc", newPackage.PkgDesc);
                        }

                        if (newPackage.PkgAgencyCommission == null)
                        {
                            cmd.Parameters.AddWithValue("@newPkgAgencyCommission", 0);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@newPkgAgencyCommission", newPackage.PkgAgencyCommission);
                        }

                        cmd.Parameters.AddWithValue("@oldPackageId", package.PackageId);
                        cmd.Parameters.AddWithValue("@oldPkgName", package.PkgName);
                        cmd.Parameters.AddWithValue("@oldPkgBasePrice", package.PkgBasePrice);
                        if (package.PkgStartDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@oldPkgStartDate", package.PkgStartDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@oldPkgStartDate", DBNull.Value);
                        }

                        if (package.PkgEndDate.HasValue)
                        {
                            cmd.Parameters.AddWithValue("@oldPkgEndDate", package.PkgEndDate);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@oldPkgEndDate", DBNull.Value);
                        }

                        if (package.PkgDesc == null)
                        {
                            cmd.Parameters.AddWithValue("@oldPkgDesc", "");
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@oldPkgDesc", package.PkgDesc);
                        }

                        if (package.PkgAgencyCommission == null)
                        {
                            cmd.Parameters.AddWithValue("@oldPkgAgencyCommission", package.PkgAgencyCommission);
                        }
                        else
                        {
                            cmd.Parameters.AddWithValue("@oldPkgAgencyCommission", 0);
                        }

                        int rowsUpdated = cmd.ExecuteNonQuery();
                        if (rowsUpdated == 0)
                        {
                            result = false;                   // did not update (another user updated or deleted)
                        }
                    }


                    return(result);
                }
            }
            catch (DBConcurrencyException ex)
            {
                throw ex;
            }
        }