backup

ajax_workshop_2/Models/Database.php

@@ -0,0 +1,45 @@
+<?php
+
+class Database {
+    /**
+     * @var Database
+     */
+    protected static $_dbInstance = null;
+
+    /**
+     * @var PDO
+     */
+    protected $_dbHandle;
+
+    /**
+     * @return Database
+     */
+    public static function getInstance() {
+
+       if(self::$_dbInstance === null) { //checks if the PDO exists
+            // creates new instance if not, sending in connection info
+            self::$_dbInstance = new self();
+        }
+        return self::$_dbInstance;
+    }
+
+    private function __construct() {
+        try { 
+             $this->_dbHandle = new PDO("sqlite:students.sqlite");
+        }
+        catch (PDOException $e) { // catch any failure to connect to the database
+	    echo $e->getMessage();
+	}
+    }
+
+    /**
+     * @return PDO
+     */
+    public function getdbConnection() {
+        return $this->_dbHandle; // returns the PDO handle to be used elsewhere
+    }
+
+    public function __destruct() {
+        $this->_dbHandle = null; // destroys the PDO handle when no longer needed
+    }
+}

ajax_workshop_2/Models/StudentData.php

@@ -0,0 +1,36 @@
+<?php
+/*
+ * Class StudentData
+ *
+ * This class models a student’s data, utilizing protected fields for data encapsulation.
+ * It takes a database row (array) as input in the constructor and assigns values to private fields, which include:
+ * - Student ID
+ * - First and Last Name
+ * - Course ID
+ * - International status (converted to 'yes' or 'no' strings for clarity)
+  */
+class StudentData {
+
+    // private fields
+    protected $_id, $_firstName, $_lastName, $_courseID, $_international;
+
+    // constructor
+    public function __construct($dbRow) {
+        $this->_id = $dbRow['student_id'];
+        $this->_firstName = $dbRow['first_name'];
+        $this->_lastName = $dbRow['last_name'];
+        if ($dbRow['international']) $this->_international = 'yes'; else $this->_international = 'no';
+        $this->_courseID = $dbRow['courseID'];
+    }
+
+    // accessors
+    public function getStudentID() {
+        return $this->_id;
+    }
+
+    // add in accessors for the other fields, check the view file in the given project to see what
+    // the accessor methods should be called
+
+}
+
+

ajax_workshop_2/Models/StudentsDataSet.php

@@ -0,0 +1,32 @@
+<?php
+
+require_once ('Database.php');
+require_once ('StudentData.php');
+
+class StudentsDataSet {
+    protected $_dbHandle, $_dbInstance;
+        
+    public function __construct() {
+        $this->_dbInstance = Database::getInstance();
+        $this->_dbHandle = $this->_dbInstance->getdbConnection();
+    }
+
+    public function fetchAllStudents(): array
+    {
+        $sqlQuery = 'SELECT * FROM students;';
+
+        $statement = $this->_dbHandle->prepare($sqlQuery); // prepare a PDO statement
+        $statement->execute(); // execute the PDO statement
+
+        $dataSet = [];
+        // loop through and read the results of the query and cast
+        // them into a matching object
+        while ($row = $statement->fetch()) {
+            $dataSet[] = new StudentData($row);
+        }
+        return $dataSet;
+    }
+
+}
+
+