June 25 - Implement reminder

config.py

@@ -329,6 +329,17 @@ def initialize_database():
             updated_at DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
         ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
         """,
+        """
+        CREATE TABLE IF NOT EXISTS shift_reminder_log (
+            user_id   INT  NOT NULL,
+            shift_id  INT  NOT NULL,
+            sent_date DATE NOT NULL,
+            sent_at   DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+            PRIMARY KEY (user_id, shift_id, sent_date),
+            FOREIGN KEY (user_id)  REFERENCES users(id)  ON DELETE CASCADE,
+            FOREIGN KEY (shift_id) REFERENCES shifts(id) ON DELETE CASCADE
+        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+        """,
     ]
 
     conn = None