diff --git a/getEvents.php b/databaseOperations.php
similarity index 51%
rename from getEvents.php
rename to databaseOperations.php
index e60f680..d102b17 100755
--- a/getEvents.php
+++ b/databaseOperations.php
@@ -25,6 +25,29 @@ function connect()
     }
 }
 
+/**
+ * @brief queries all the categories from the dabase
+ * @param $db: the PDO connection to the database
+ * @return al list of all the categories (id, name)
+ */
+function getCategories($db)
+{
+    try
+    {
+        $request = $db->prepare('SELECT * FROM categorie NATURAL JOIN sous_categorie ORDER BY sous_cat_tab ASC, sous_cat_id ASC');
+        $request->execute();
+        $result = $request->fetchAll();
+        $request->closeCursor();
+        return $result;
+    }
+    catch(PDOException $e)
+    {
+        //NOTE: change $e->getMessage() by an error message before going to production
+        echo($e->getMessage());
+        die();
+    }
+}
+
 /**
  * @brief queries all the events from the database
  * @param $db: the PDO connection to the database
@@ -34,7 +57,7 @@ function getAllEvents($db)
 {
     try
     {
-        $request = $db->prepare('SELECT events.id, events.titre, events.localisation, events.dtstart, events.dtend, events.description FROM events, categorie WHERE events.categorie = categorie.id ');
+        $request = $db->prepare('SELECT * FROM event NATURAL JOIN eventCategorie NATURAL JOIN categorie');
         $request->execute(array('date'=>date("Y-m-d",$date)));
         $result = $request->fetchAll();
         $request->closeCursor();
@@ -58,7 +81,25 @@ function getOneEvent($db, $id)
 {
     try
     {
-        $request = $db->prepare('SELECT events.id, events.titre, events.localisation, events.dtstart, events.dtend, events.description FROM events, categorie WHERE events.categorie = categorie.id AND events.id = ?');
+        $request = $db->prepare('SELECT * FROM event WHERE event_id = ?');
+        $request->execute(array($id));
+        $result = $request->fetch();
+        $request->closeCursor();
+        return $result;
+    }
+    catch(PDOException $e)
+    {
+        //NOTE: change $e->getMessage() by an error message before going to production
+        echo($e->getMessage());
+        die();
+    }
+}
+
+function getCategoriesForOneEvent($db, $eventId)
+{
+    try
+    {
+        $request = $db->prepare('SELECT * FROM eventCategorie NATURAL JOIN categorie NATURAL JOIN sous_categorie ORDER BY sous_cat_tab ASC, sous_cat_id ASC WHERE event_id = ?');
         $request->execute(array($id));
         $result = $request->fetch();
         $request->closeCursor();
@@ -82,7 +123,7 @@ function getEventsByDate($db, $date)
 {
     try
     {
-        $request = $db->prepare('SELECT events.id, events.titre, events.localisation, events.dtstart, events.dtend, events.description FROM events, categorie WHERE events.categorie = categorie.id AND (dtstart <= :date AND dtend >= :date)');
+        $request = $db->prepare('SELECT * FROM event WHERE (event_dtstart <= :date AND event_dtend >= :date)');
         $request->execute(array('date'=>date("Y-m-d",$date)));
         $result = $request->fetchAll();
         $request->closeCursor();
@@ -97,17 +138,21 @@ function getEventsByDate($db, $date)
 }
 
 /**
- * @brief queries the database for the events after a certain date
+ * @brief queries the database for the events on a certain date, where the categories are matched
  * @param $db: the PDO connection to the database
  * @param $date: the date to search for
- * @return a list of all the events future to $date
+ * @param $categories: an array containing the IDs of the categories
+ * @return a list of all the events of the different categories at the date $date
  */
-function getEventsSince($db,$date)
+function getEventsByDateAndCategories($db, $date, $categories)
 {
     try
     {
-        $request = $db->prepare('SELECT events.id, events.titre, events.localisation, events.dtstart, events.dtend, events.description FROM events, categorie WHERE events.categorie = categorie.id AND (events.dtstart >= :date OR events.dtend >= :date)');
-        $request->execute(array('date'=>date("Y-m-d",$date)));
+        $request = $db->prepare('SELECT * FROM event NATURAL JOIN eventCategorie NATURAL JOIN categorie WHERE (dtstart <= :date AND dtend >= :date) AND events.categorie IN (:categories)');
+        $request->execute(array(
+                                    'date'=>date("Y-m-d",$date),
+                                    'categories'=>implode(',', array_map('intval', $categories))
+        ));
         $result = $request->fetchAll();
         $request->closeCursor();
         return $result;
@@ -121,28 +166,26 @@ function getEventsSince($db,$date)
 }
 
 /**
- * @deprecated
- */
-function getEvents()
-{
-    //FUTURE: delete this function
-    $pdo = connect();
-    $stmt = $pdo->prepare('SELECT titre, localisation, dtstart, dtend, description, url FROM events, categorie WHERE events.categorie = categorie.id');
-    $stmt->execute();
-    $result = $stmt->fetchAll();
-    return $result;
-}
-
-/**
- * @deprecated
+ * @brief queries the database for the events after a certain date
+ * @param $db: the PDO connection to the database
+ * @param $date: the date to search for
+ * @return a list of all the events future to $date
  */
-function getEvent($id)
+function getEventsSince($db,$date)
 {
-    //FUTURE: delete this function
-    $pdo = connect();
-    $stmt = $pdo->prepare('SELECT titre, localisation, dtstart, dtend, description, url FROM events WHERE id = ?');
-    $stmt->execute(array($id));
-    $result = $stmt->fetch();
-    return $result;
+    try
+    {
+        $request = $db->prepare('SELECT * FROM event WHERE (event_dtstart >= :date OR event_dtend >= :date)');
+        $request->execute(array('date'=>date("Y-m-d",$date)));
+        $result = $request->fetchAll();
+        $request->closeCursor();
+        return $result;
+    }
+    catch(PDOException $e)
+    {
+        //NOTE: change $e->getMessage() by an error message before going to production
+        echo($e->getMessage());
+        die();
+    }
 }
 ?>
diff --git a/export.php b/export.php
index 5382e43..0a522f3 100644
--- a/export.php
+++ b/export.php
@@ -13,7 +13,7 @@ function icaldate($date)
     return date('Ymd',$dt).'T'. date('His',$dt). 'Z';
 }
 
-include_once('getEvents.php');
+include_once('databaseOperations.php');
 $db = connect();
 $events = getEventsSince($db, strtotime('last monday +'.$weekOffset.' weeks'));
 
diff --git a/index.php b/index.php
index c706cab..9e8ef70 100644
--- a/index.php
+++ b/index.php
@@ -1,6 +1,6 @@
 <?php
 session_start();
-include_once('getEvents.php');
+include_once('databaseOperations.php');
 $db = connect();
 
 $days = array(
@@ -32,6 +32,8 @@ if(isset($_GET['w'])&&is_numeric($_GET['w']))
 else
     $weekOffset = 0;
 
+$categories = getCategories($db);
+
 ?>
 <!DOCTYPE html>
 <html>
diff --git a/makedatabase.sql b/makedatabase.sql
index 39904e5..a761bf6 100644
--- a/makedatabase.sql
+++ b/makedatabase.sql
@@ -1,7 +1,7 @@
-CREATE TABLE sous_categorie(sous_cat_id INTEGER PRIMARY KEY, sous_cat_titre VARCHAR(255));
+CREATE TABLE sous_categorie(sous_cat_id INTEGER PRIMARY KEY, sous_cat_tab INTEGER NOT NULL, sous_cat_titre VARCHAR(255) NOT NULL);
 
-CREATE TABLE categorie(cat_id INTEGER PRIMARY KEY, cat_titre VARCHAR(255), sous_cat_id INTEGER, FOREIGN KEY(sous_cat_id) REFERENCES sous_categorie(sous_cat_id));
+CREATE TABLE categorie(cat_id INTEGER PRIMARY KEY, cat_titre VARCHAR(255) NOT NULL, sous_cat_id INTEGER NOT NULL, FOREIGN KEY(sous_cat_id) REFERENCES sous_categorie(sous_cat_id));
 
-CREATE TABLE event(event_id INTEGER PRIMARY KEY, event_titre VARCHAR(255), event_localisation VARCHAR(255), event_dtstart DATETIME, event_dtend DATETIME, event_description TEXT, event_url VARCHAR(255));
+CREATE TABLE event(event_id INTEGER PRIMARY KEY, event_titre VARCHAR(255) NOT NULL, event_localisation VARCHAR(255) NOT NULL, event_dtstart DATETIME NOT NULL, event_dtend DATETIME NOT NULL, event_description TEXT NOT NULL, event_url VARCHAR(255) NULL);
 
 CREATE TABLE eventCategorie(event_id INTEGER, cat_id INTEGER, FOREIGN KEY(event_id) REFERENCES event(event_id), FOREIGN KEY(cat_id) REFERENCES categorie(cat_id));