add schemas

src/schemas/database.py

@@ -6,20 +6,20 @@ usermail TEXT NOT NULL);
 MEDIA = """CREATE TABLE IF NOT EXISTS media (
 id INTEGER PRIMARY KEY AUTOINCREMENT,
 signature TEXT NOT NULL,
-isbn TEXT NOT NULL,
-ppn TEXT NOT NULL,
+isbn TEXT,
+ppn TEXT,
 title TEXT NOT NULL,
-link TEXT NOT NULL);
+link TEXT);
 """
 
 LOANS = """CREATE TABLE IF NOT EXISTS loans (
 id INTEGER PRIMARY KEY AUTOINCREMENT,
 user_id INTEGER NOT NULL,
 media_id INTEGER NOT NULL,
-loan_date TEXT NOT NULL,
-return_date TEXT NOT NULL,
+loan_date DATETIME NOT NULL,
+return_date DATETIME NOT NULL,
 returned INTEGER DEFAULT 0,
-returned_date TEXT,
+returned_date DATETIME,
 FOREIGN KEY (user_id) REFERENCES users(id),
 FOREIGN KEY (media_id) REFERENCES media(id));
 """