refactor: Refactor storage system (#937)

pilot/meta_data/alembic/env.py

@@ -3,7 +3,7 @@ from sqlalchemy import pool
 
 from alembic import context
 
-from dbgpt.storage.metadata.meta_data import Base, engine
+from dbgpt.storage.metadata.db_manager import db
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.
@@ -13,8 +13,7 @@ config = context.config
 # add your model's MetaData object here
 # for 'autogenerate' support
 # from myapp import mymodel
-# target_metadata = mymodel.Base.metadata
-target_metadata = Base.metadata
+
 
 # other values from the config, defined by the needs of env.py,
 # can be acquired:
@@ -34,6 +33,8 @@ def run_migrations_offline() -> None:
     script output.
 
     """
+    engine = db.engine
+    target_metadata = db.metadata
     url = config.get_main_option(engine.url)
     context.configure(
         url=url,
@@ -53,12 +54,8 @@ def run_migrations_online() -> None:
     and associate a connection with the context.
 
     """
-    connectable = engine_from_config(
-        config.get_section(config.config_ini_section, {}),
-        prefix="sqlalchemy.",
-        poolclass=pool.NullPool,
-    )
-
+    engine = db.engine
+    target_metadata = db.metadata
     with engine.connect() as connection:
         if engine.dialect.name == "sqlite":
             context.configure(