Widhy Hayuhardhika NP, S.Kom

Building an online bidding application using

PHP/MySQL

Outline Topic #1 MySQL Connection

Overview of database structureConnecting to MySQL databaseSelecting the database to useUsing the require_once statement

MySQL Database Connection

Database: auctionTables

tblaccounttblbiditemstblbidhistory

Overview of Database connection

This will hold the account info of bidders/ auctioneers

Table structureColumn accountid: integer, primary key, auto-

incrementColumn username: string 50 charsColumn password: string 50 chars

Table tblaccount

This will hold the items auctioned for biddingTable structure

Column biditemid: integer , primary key, auto-increment

Column accountid: string 50 charsThis identifies the auctioneer

Column biditem: string 50 charsColumn biddesc: tiny text

Table tblbiditems

This will hold the bid info for each item being auctioned

Table structureColumn bidhistoryid: integer , primary key,

auto-incrementColumn accountid: integerColumn biditemid: integerColumn bidprice: doubleColumn dtesubmitted: datetime

Table tblbidhistory

Function mysql_connect:Creates a connection to MySQLSyntax: mysql_connect($hostname, $username,

$password)Ex: $conn=mysql_connect(“localhost”,

“root”,”password”)Function mysql_select_db

Specifies the database in MySQL for useSyntax: mysql_select_db($database,

$connection)Ex: mysql_select_db(“auction”, $conn)

Function dieTerminates execution of PHP script

Connecting to databases:

Create file dbconnect.incFor code reuse, a separate file can be created

to connect to the databasePHP pages can call dbconnect.inc to connect

yo the auction database

Connecting to MySQL and selecting auction database

Function require_once()Loads a file into a PHP script

Reusing the database connection

Outline Topic #2 Creation of Accounts

HTML form handlingMySQL commands

Function mysql_query()Function mysql_error()

Adding recordsSQL insert statement

Creation of accounts

Create:File index.htmlFile addaccount.htmlFile addaccountprocess.php

$_POST array

HTML form handling

First page that displaysProvide the user with the option to create

accounts

File index.html

Displays a form for accepting new account info

File addaccount.html

$_POST arraySpecial arrays that hold all form variables

Function mysql_query()Executes an SQL statement on the database

Function mysql_error()Displays error encountered when executing an

SQL statementSQL Insert

Adds a record on a database table

File addaccountprocess.php

File addaccountprocess.php script

Username: auctioneer1This account will place items for bidding

Usernames: bidder1, bidder2These account will bid for item auctioned off

Create accounts:

Outline Topic #3 Managing Logins

SQL select statementFunction mysql_num_rowsFunction isset()SessionURL rewriting

Querystring $_GET array

Create: File login.php File loginverify.php File checkstatus.inc File menu.php

Managing logins

Example 1: select * from tblaccount Selects all columns/ rows from table tblaccount

Example 2: select username, password from tblaccount Selects columns username and password for all rows in

table tblaccountExample 3: select * from tblaccount where

username=‘jundolor’ Selects all columns from table tblaccount for all rows

whose column username contains ‘jundolor’Example 4: select accountid from tblaccount

where username=‘media’ Selects column accountid from tblaccount for all rows

whose column username contains ‘media’

SQL select statement

Retrieves the number of rows from a result set

Can only be used for SQL select statements

Function mysql_num_rows

Checks if a variable existExample: isset($name)

This check if the variable $name exist

Function isset()

Special variables stored in web serversAllows passing of information between web

pagesCall the function session_start() at the start of

scripts that will use sessions

Sessions

QuerystringInformation can be passed on by appending

variable/value to the URL

$_GET arraySpecial array that holds all querystring values

URL Rewriting

File login.php code

File login.php browser shot

File loginverify.php code

File checkstatus.inc code

File menu.php

Outline Topic #4 Adding Items to Auction

File menu.phpCreate:

File addauctionitem.phpFile addauctionitemprocess.php

Adding items to auction

File menu.php

File addauctionitem.php code

File addauctionitem.php screen shot

File addauctionprocess.php

Outline Topic #5 Deleting Bid Items

Function mysql_fetch_array()Writing querystring URL to identify records

to deleteSQL delete statementCreate:

File listauctionitems.phpFile: deletebiditem.php

Deleting Bid Items

Fetches a row as an associative from a select query result set

Function mysql_fetch_array()

Sample mysql_fetch_array() code

Auction items belonging to current account will be selected

A loop will be created to go through each rowEach row will hyperlink to a PHP based page

for deletionTo identify the row, a querystring variable will

be appended to the URL

Writing querystring URLto identify records to delete

Writing querystring URLto identify records to delete- code

Example 1: delete from tblaccountDeletes all rows on table tblaccount

Example 2: delete from tblaccount where accountid=1Deletes only rows matching the condition

SQL delete statement

File menu.php

File listauctionitems.php

File deletebiditem.php

Outline Topic #6 Logging Out

Function session_destroy()Create:

File logout.php

Loggin out

Terminates all session variables stored in server memory

Function session_destroy()

File menu.php

Once logout.php is called, all session variable will be dropped from server memory

Browser will not be able to access any page calling checkverify.php (ex: menu.php)

File logout.php

Outline Topic #7 Viewing Bid Items

Establishing relations between tablesSQL natural join clauseCreate:

File listbiditems.php

Viewing bid items

Establishing relationsTable tblbiditem

Holds the items being auctioned off

Column accountid identifies the owner if the auctioned item

Table tblaccount Holds account

information of the owner of the item being auctioned

Column accountid Links the owner of the

account to the auction item

Used with SQL select statementConnects rows between different tables via

their common column

SQL natural join clause

File menu.php

All items with their respective owners being auction are listed

Each item will hyperlink to a PHP page for accepting bidsAccepting bids will be covered in the next topic

sectionEach hyperlink will append a querystring

variable to identify it in the PHP page for accepting bids

File listbiditems.php

File listbiditems.php code

File listbiditems.php screen shot

Outline Topic #7 Accepting Bids

Using hidden fields to store ID numbersMySQL now() functionCreate:

File acceptbid.phpFile acceptbidprocess.php

Accepting bids

Not displayed to the browserUsed to pass constant values

Hidden fields

Place the id of the auction item in a hidden fieldFile acceptbid.php

File acceptbid.php screen shot

File acceptbid.php HTML generated code

Returns the current date and time as a value in 'YYYY-MM-DD HH:MM:SS' or YYYYMMDDHHMMSS.uuuuuu formatdepending on whether the function is used in a

string or numeric contextThe value is expressed in the current time

zone.

MySQL now() function

File acceptbidprocess.php

Resulting records

Outline Topic #9 Listing Bids For Each Bid Item

MySQL date_format() functionRelating information from two or more tablesSQL order by clause

Listing bids for each bid item

Formats a string based on a specified formatThe following are some of the specifies of the

format string:%D: Day of month with English suffix%d: Numeric day of month (01…31)%M: Month name (January…December)%m: Month numeric (01…12)%Y: Year (4 digits)%y: Year (2 digits)

MySQL date_format() function

MySQL date_format() sample