fix removal feed, refactor return id and add type hints

database.py

@@ -1,5 +1,6 @@
-import psycopg2
+import psycopg2 
-import psycopg2.extras
+from psycopg2.extensions import connection
+from psycopg2.extras import DictCursor, DictRow
 
 from logging import Logger
 
@@ -14,16 +15,16 @@ class Database:
         """Create a database file if not exists."""
         self.log: Logger = log
         self.log.debug('Database.__init__(DSN=\'%s\')', dsn)
-        self.conn = psycopg2.connect(dsn)
+        self.conn: connection = psycopg2.connect(dsn)
-        self.cur = self.conn.cursor(cursor_factory=psycopg2.extras.DictCursor)
+        self.cur: DictCursor = self.conn.cursor(cursor_factory=DictCursor)
         self.__init_schema()
 
     def add_user(self, telegram_id: int) -> int:
         """Add a user's telegram id to the database and return its database id."""
         self.log.debug('add_user(telegram_id=\'%s\')', telegram_id)
-        self.cur.execute('INSERT INTO users (telegram_id) VALUES (%s)', [telegram_id])
+        id = self.cur.execute('INSERT INTO users (telegram_id) VALUES (%s) RETURNING id', [telegram_id])
         self.conn.commit()
-        return self.find_user(telegram_id)
+        return id
 
     def find_user(self, telegram_id: int) -> int | None:
         """Get a user's telegram id and return its database id."""
@@ -37,9 +38,9 @@ class Database:
     def add_feed(self, url: str) -> int:
         """Add a feed to the database and return its id."""
         self.log.debug('add_feed(url=\'%s\')', url)
-        self.cur.execute('INSERT INTO feeds (url) VALUES (%s)', [url])
+        id = self.cur.execute('INSERT INTO feeds (url) VALUES (%s) RETURNING id', [url])
         self.conn.commit()
-        return self.find_feed_by_url(url)
+        return id
 
     def find_feed_by_url(self, url: str) -> int | None:
         """Find feed ID by url."""
@@ -126,14 +127,14 @@ class Database:
         self.cur.execute('SELECT * FROM feeds')
         return self.cur.fetchall()
 
-    def find_user_feeds(self, user_id: int) -> list[psycopg2.extras.DictRow]:
+    def find_user_feeds(self, user_id: int) -> list[DictRow]:
         """Return a list of feeds the user is subscribed to."""
         self.log.debug('find_user_feeds(user_id=\'%s\')', user_id)
         self.cur.execute('SELECT * FROM feeds WHERE id IN (SELECT feed_id FROM subscriptions WHERE user_id = %s)',
                          [user_id])
         return self.cur.fetchall()
 
-    def find_feed_items(self, feed_id: int) -> list[psycopg2.extras.DictRow]:
+    def find_feed_items(self, feed_id: int) -> list[DictRow]:
         """Get last feed items."""
         self.log.debug('find_feed_items(feed_id=\'%s\')', feed_id)
         self.cur.execute('SELECT * FROM feeds_last_items WHERE feed_id = %s', [feed_id])
@@ -166,19 +167,16 @@ class Database:
         self.cur.execute('CREATE TABLE IF NOT EXISTS feeds (id SERIAL PRIMARY KEY, url TEXT NOT NULL UNIQUE)')
         self.cur.execute(
             'CREATE TABLE IF NOT EXISTS subscriptions ('
-            '   user_id INTEGER,'
+            '   user_id INTEGER REFERENCES users,'
-            '   feed_id INTEGER,'
+            '   feed_id INTEGER REFERENCES feeds,'
-            '   UNIQUE (user_id, feed_id),'
+            '   UNIQUE (user_id, feed_id)'
-            '   FOREIGN KEY(user_id) REFERENCES users(id),'
-            '   FOREIGN KEY(feed_id) REFERENCES feeds(id)'
             ')'
         )
         self.cur.execute(
             'CREATE TABLE IF NOT EXISTS feeds_last_items ('
-            '   feed_id INTEGER,'
+            '   feed_id INTEGER REFERENCES feeds ON DELETE CASCADE,'
             '   url TEXT NOT NULL,'
             '   title TEXT,'
-            '   description TEXT,'
+            '   description TEXT'
-            '   FOREIGN KEY(feed_id) REFERENCES feeds(id)'
             ')'
         )