Implemented alembic migrations, added cursors closing task.

alembic/env.py

@@ -0,0 +1,80 @@
+from logging.config import fileConfig
+
+from data.db import engine
+from data.models import Base
+
+from alembic import context
+
+
+"""
+    Create migration example:
+    > alembic -c alembic/alembic.ini revision --autogenerate -m "Added pool size config to the connection model."
+
+    Migrate example:
+    > alembic -c alembic/alembic.ini upgrade head
+"""
+
+
+config = context.config
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+from data.models import User, Query, Connection
+
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    """
+    Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    Calls to context.execute() here emit the given string to the
+    script output.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_migrations_online() -> None:
+    """
+    Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+
+    connectable = engine
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_migrations)
+
+
+def do_migrations(connection):
+    context.configure(connection=connection, target_metadata=Base.metadata)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    import asyncio
+
+    asyncio.run(run_migrations_online())