I just want the tutorial

flaskr/db.py

@@ -0,0 +1,52 @@
+import sqlite3
+
+import click
+from flask import current_app
+from flask import g
+
+
+def get_db():
+    """Connect to the application's configured database. The connection
+    is unique for each request and will be reused if this is called
+    again.
+    """
+    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):
+    """If this request connected to the database, close the
+    connection.
+    """
+    db = g.pop("db", None)
+
+    if db is not None:
+        db.close()
+
+
+def init_db():
+    """Clear existing data and create new tables."""
+    db = get_db()
+
+    with current_app.open_resource("schema.sql") as f:
+        db.executescript(f.read().decode("utf8"))
+
+
+@click.command("init-db")
+def init_db_command():
+    """Clear existing data and create new tables."""
+    init_db()
+    click.echo("Initialized the database.")
+
+
+def init_app(app):
+    """Register database functions with the Flask app. This is called by
+    the application factory.
+    """
+    app.teardown_appcontext(close_db)
+    app.cli.add_command(init_db_command)