implemented database, article cards, and parsing from markdown.

functions/db_functions.php

@@ -0,0 +1,53 @@
+<?php
+// Use environment variables for the database password and IP address.
+$db_user = $_ENV['DATABASE_USER'];
+$db_pass = $_ENV['DATABASE_PASSWORD'];
+$ip_addr = $_ENV['IP_ADDRESS'];
+
+// Make some constants
+if ($_SERVER['HTTP_HOST'] == 'localhost') {
+    define('HOST', 'localhost');
+    define('USER', $db_user);
+    define('PASS', $db_pass);
+    define('DB', 'vintagecoding');
+} else {
+    define('HOST', $ip_addr);
+    define('USER', $db_user);
+    define('PASS', $db_pass);
+    define('DB', 'vintagecoding');
+}
+
+/*
+ * Handles any queries that should have only one row results.
+ */
+function query_db_one_result($query_stmt)
+{
+    $conn = get_connection();
+    $results = mysqli_query($conn, $query_stmt);
+    mysqli_close($conn);
+
+    if (mysqli_num_rows($results) == 0 || mysqli_num_rows($results) > 1)
+        return null;
+    else
+        return mysqli_fetch_assoc($results);
+}
+
+function query_db_one_or_more_results($query_stmt)
+{
+    $conn = get_connection();
+    $results = mysqli_query($conn, $query_stmt);
+    mysqli_close($conn);
+
+    if (mysqli_num_rows($results) == 0)
+        return null;
+    else
+        return $results;
+}
+
+function get_connection()
+{
+    // Connect to the DB
+    $conn = mysqli_connect(HOST, USER, PASS, DB);
+
+    return $conn;
+}