Edit of links and database versioning

backend/app/database.py

@@ -13,7 +13,8 @@ AVATARS_DIR.mkdir(parents=True, exist_ok=True)
 def hash_password(password: str) -> str:
     return sha256(password.encode('utf-8')).hexdigest()
 
-SCHEMA = '''
+MIGRATIONS = [
+    (1, '''
 CREATE TABLE IF NOT EXISTS users (
     id TEXT PRIMARY KEY,
     username TEXT NOT NULL UNIQUE,
@@ -70,7 +71,8 @@ CREATE TABLE IF NOT EXISTS user_plugin_config (
     UNIQUE(user_id, plugin_name),
     FOREIGN KEY(user_id) REFERENCES users(id)
 );
-'''
+'''),
+]
 
 
 def get_connection() -> sqlite3.Connection:
@@ -80,9 +82,23 @@ def get_connection() -> sqlite3.Connection:
     return conn
 
 
+def get_schema_version(conn: sqlite3.Connection) -> int:
+    return conn.execute('PRAGMA user_version').fetchone()[0]
+
+
+def apply_migrations(conn: sqlite3.Connection) -> None:
+    current_version = get_schema_version(conn)
+    for version, sql in MIGRATIONS:
+        if version <= current_version:
+            continue
+        conn.executescript(sql)
+        conn.execute(f'PRAGMA user_version = {version}')
+    conn.commit()
+
+
 def init_db() -> None:
     with get_connection() as conn:
-        conn.executescript(SCHEMA)
+        apply_migrations(conn)
         alice_hash = hash_password('secret123')
         bob_hash = hash_password('secret123')
         conn.execute(