Data transfer script (#114)

Transfers data betwenn two sql instances.
Limited in data volume. Should be good enough for now.

---------

Co-authored-by: Tim <tim.ronneburg@outlook.de>

tests/utils/sql/connector_test.py

@@ -4,15 +4,19 @@ from collections.abc import Generator
 from typing import Any
 from unittest.mock import Mock, patch
 
+import pandas as pd
 import pytest
 from sqlalchemy.engine import Engine
+from sqlalchemy.orm import Session
 
 from aki_prj23_transparenzregister.config.config_providers import JsonFileConfigProvider
 from aki_prj23_transparenzregister.config.config_template import PostgreConnectionString
 from aki_prj23_transparenzregister.utils.sql.connector import (
+    Base,
     get_pg_engine,
     get_session,
     init_db,
+    transfer_db,
 )
 
 
@@ -27,6 +31,36 @@ def test_get_engine_pg() -> None:
         assert get_pg_engine(conn_args) == result
 
 
+@pytest.fixture()
+def destination_db() -> Generator[Session, None, None]:
+    """Generates a db Session to a sqlite db to copy data to."""
+    if os.path.exists("secondary.db"):
+        os.remove("secondary.db")
+    db = get_session("sqlite:///secondary.db")
+    init_db(db)
+    yield db
+    db.close()
+    bind = db.bind
+    assert isinstance(bind, Engine)
+    bind.dispose()
+    os.remove("secondary.db")
+
+
+def test_transfer_db(full_db: Session, destination_db: Session) -> None:
+    """Tests if the data transfer between two sql tables works."""
+    transfer_db(source=full_db, destination=destination_db)
+    sbind = full_db.bind
+    dbind = destination_db.bind
+    assert isinstance(sbind, Engine)
+    assert isinstance(dbind, Engine)
+
+    for table in Base.metadata.sorted_tables:
+        pd.testing.assert_frame_equal(
+            pd.read_sql_table(str(table), dbind),
+            pd.read_sql_table(str(table), sbind),
+        )
+
+
 @pytest.fixture()
 def delete_sqlite_table() -> Generator[str, None, None]:
     """Cleans a path before and deletes the table after a test.