>> PHP: MySQL & CRUD

R ecall Database Tables Records is composed of Operations (CRUD) Create Retrieve Update Delete DBMS Access Control MySQL phpMyAdmin Web-Based Systems - Misbhauddin 2

phpMyAdmin Click Here Web-Based Systems - Misbhauddin 3

Collation character set is a set of symbols and encodings Collation is a set of rules for comparing characters in a character set In latin9, there are letters as e é è ê f If sorted by their binary representation, it will go "e f é ê è" MySQL can do these things for you: Store strings using a variety of character sets Compare strings using a variety of collations Mix strings with different character sets or collations in the same server, the same database, or even the same table Enable specification of character set and collation at any level Web-Based Systems - Misbhauddin 4

Database Operations Create User Create Database Create Table Insert Records in the Table DEMO Web-Based Systems - Misbhauddin 5

Database Connection from PHP Pre-requisite – Create a new file in your project – Name it connection-db.php WHY? – To avoid typing the database connection commands in PHP each time we connect Remember – HTTP is a stateless protocol Procedure to connect to the database Step 1: Create and initialize the required connection variables Host-Name ($host = ‘localhost’;) User Name ($user = ‘your-username’;) Password ($pwd = ‘your-password’;) Database Name ($db = ‘store’;) Web-Based Systems - Misbhauddin 6

Database Connection from PHP Step 2: Create the connection variable $con = mysqli_connect($host,$user,$pwd,$db); Step 3: Check for success & failure (optional) if(mysqli_connect_errno($con)) { echo mysqli_connect_error(); } Step 4: Include this connection file inside any php file that needs connection to the database Web-Based Systems - Misbhauddin 7

Running a Query Process to Construct & Run a MySQL Query Step 1: Construct the query, preferably in a variable $query = ‘SELECT * FROM stuff’; Step 2: Run the Query $result = mysqli_query($con, $query); Step 3: Fetch the Results (In a regular array): mysqli_fetch_array($result) (In an associative array): mysqli_fetch_assoc($result) Web-Based Systems - Misbhauddin 8

Issues with result processing Step 3: Fetch the Results (In a regular array): mysqli_fetch_array($result) (In an associative array): mysqli_fetch_assoc($result) Result is returned row-by-row AND foreach loop statement in PHP requires the complete array at a time Solution? Web-Based Systems - Misbhauddin 9 Hint: Is for each necessary inside the while loop? Maybe not. ☻

Issues with result processing Step 3: Fetch the Results (In a regular array): mysqli_fetch_array($result) (In an associative array): mysqli_fetch_assoc($result) Result is returned row-by-row AND foreach loop statement in PHP requires the complete array at a time Solution while ($row = mysqli_fetch_assoc($result)) { $stuff[$row[‘ID’]] = array( "name" => $row[‘Name’], "img" => $row[‘Image’], "price" => $row[‘Price’] ); } 10 Web-Based Systems - Misbhauddin

Next on Web-based Systems Web-Based Systems - Misbhauddin 11 Next Class – Form Handling in PHP – Add Items to the Database