diff --git a/app/database.py b/app/database.py
index a706d41..8ca48b9 100644
--- a/app/database.py
+++ b/app/database.py
@@ -10,37 +10,33 @@ class Database:
             password=app.config["DB_PASSWORD"],
             database=app.config["DB_DATABASE"]
         )
+        self.cur = self.db.cursor()
 
     def create_session(self, username, password):
-        cursor = self.db.cursor()
-        cursor.execute("SELECT user_id FROM utilisateurs WHERE username=%s AND password=%s", (username, password))
+        self.cur.execute("SELECT user_id FROM utilisateurs WHERE username=%s AND password=%s", (username, password))
 
-        if result := cursor.fetchall():
+        if result := self.cur.fetchall():
             user_id = result[0][0]
         else:
             return None
 
         uuid = str(uuid4())
-        cursor.execute("INSERT INTO sessions (session_id, user_id) VALUES (%s, %s)", (uuid, user_id))
+        self.cur.execute("INSERT INTO sessions (session_id, user_id) VALUES (%s, %s)", (uuid, user_id))
         self.db.commit()
-        cursor.close()
         return uuid
 
     def destroy_session(self, uuid):
-        cursor = self.db.cursor()
-        cursor.execute("DELETE FROM sessions WHERE session_id=%s", (uuid,))
+        self.cur.execute("DELETE FROM sessions WHERE session_id=%s", (uuid,))
         self.db.commit()
-        cursor.close()
 
     def check_connection(self, uuid):
-        cursor = self.db.cursor()
-        cursor.execute("DELETE FROM sessions WHERE expiry_date <= CURRENT_TIMESTAMP")
-        cursor.execute("SELECT session_id FROM sessions WHERE session_id=%s", (uuid,))
-        result = cursor.fetchall()
-        cursor.close()
+        self.cur.execute("DELETE FROM sessions WHERE expiry_date <= CURRENT_TIMESTAMP")
+        self.cur.execute("SELECT session_id FROM sessions WHERE session_id=%s", (uuid,))
+        result = self.cur.fetchall()
         return result
     
     def __del__(self):
+        self.cur.close()
         self.db.close()
 
 class User:
@@ -58,21 +54,17 @@ class Session:
         self.user = self.get_user()
 
     def get_user(self):
-        cursor = self.db.db.cursor()
-        cursor.execute("SELECT utilisateurs.user_id, username, nom, prenom, creation_date FROM utilisateurs "
+        self.db.cur.execute("SELECT utilisateurs.user_id, username, nom, prenom, creation_date FROM utilisateurs "
                        "JOIN sessions ON utilisateurs.user_id=sessions.user_id WHERE session_id=%s", (self.uuid,))
-        result = cursor.fetchall()
-        cursor.close()
+        result = self.db.cur.fetchall()
         return User(*result[0])
 
     def fetch_grades(self):
-        cursor = self.db.db.cursor()
-        cursor.execute("SELECT matieres.libelle, devoirs.libelle, date, coefficient, valeur, maximum FROM notes "
+        self.db.cur.execute("SELECT matieres.libelle, devoirs.libelle, date, coefficient, valeur, maximum FROM notes "
                        "JOIN devoirs ON notes.id_devoir=devoirs.id_devoir "
                        "JOIN matieres ON devoirs.id_matiere=matieres.id_matiere WHERE id_eleve=%s", (self.user.id,))
 
-        result = cursor.fetchall()
-        cursor.close()
+        result = self.db.cur.fetchall()
         dico = {}
         for note in result:
             if note[0] in dico: