added functions for handling database connection

the_works/database.py

@@ -0,0 +1,28 @@
+import sqlite3
+import click
+from flask import current_app, g
+
+def init_app(app):
+  app.teardown_appcontext(close_db)
+  app.cli.add_command(init_db_command)
+
+@click.command("init-db")
+def init_db_command():
+  db = get_db()
+  with current_app.open_resource("schema.sql") as f:
+    db.executescript(f.read().decode("utf-8"))
+  click.echo("You successfully initialized the database!")
+
+def get_db():
+  if "db" not in g:
+    g.db = sqlite3.connect(
+      current_app.config["DATABASE"],
+      detect_types=sqlite3.PARSE_DECLTYPES,
+    )
+    g.db.row_factory = sqlite3.Row
+  return g.db
+
+def close_db(e=None):
+  db = g.pop("db", None)
+  if db is not None:
+    db.close()