Display devices and there status

db.py

@@ -42,3 +42,17 @@ class DataBase():
 
     def get_all_cadences(self):
         return self.execute('SELECT * FROM cadence')
+
+    def get_devices(self):
+        return self.execute("""
+        SELECT DEVICE.ID,
+	        DEVICE.NAME,
+	        MAX(CADENCE.LOGGED_AT) AS LAST_LOGGED_AT,
+	        CASE WHEN(NOW() < (MAX(CADENCE.LOGGED_AT) + (INTERVAL '5 min'))) THEN 'yes'
+				ELSE 'no'
+	        END AS IS_ACTIVE
+        FROM DEVICE
+        LEFT JOIN CADENCE ON DEVICE.ID = CADENCE.DEVICE_ID
+        GROUP BY DEVICE.ID
+        ORDER BY LAST_LOGGED_AT
+        """)