update database schema

src/schemas/database.py

@@ -8,7 +8,8 @@ id INTEGER PRIMARY KEY AUTOINCREMENT,
 signature TEXT NOT NULL,
 isbn TEXT NOT NULL,
 ppn TEXT NOT NULL,
-title TEXT NOT NULL);
+title TEXT NOT NULL,
+link TEXT NOT NULL,);
 """
 
 LOANS = """CREATE TABLE IF NOT EXISTS loans (
@@ -17,6 +18,7 @@ user_id INTEGER NOT NULL,
 media_id INTEGER NOT NULL,
 loan_date TEXT NOT NULL,
 return_date TEXT NOT NULL,
+returned INTEGER DEFAULT 0,
 FOREIGN KEY (user_id) REFERENCES users(id),
 FOREIGN KEY (media_id) REFERENCES media(id));
 """