diff --git a/tests/test_transform.py b/tests/test_transform.py index f0f5019a6..3cc5ba60c 100644 --- a/tests/test_transform.py +++ b/tests/test_transform.py @@ -432,6 +432,43 @@ def test_transform_verify_foreign_keys(fresh_db): assert fresh_db.conn.execute("PRAGMA foreign_keys").fetchone()[0] +@pytest.mark.parametrize("use_pragma_foreign_keys", [False, True]) +def test_transform_on_delete_cascade_does_not_delete_records( + fresh_db, use_pragma_foreign_keys +): + # Transforming a table drops and recreates it - if another table references + # it with ON DELETE CASCADE and PRAGMA foreign_keys is on, that drop must + # not cascade and delete the referencing records + if use_pragma_foreign_keys: + fresh_db.conn.execute("PRAGMA foreign_keys=ON") + fresh_db.executescript(""" + CREATE TABLE authors (id INTEGER PRIMARY KEY, name TEXT); + CREATE TABLE books ( + id INTEGER PRIMARY KEY, + title TEXT, + author_id INTEGER REFERENCES authors(id) ON DELETE CASCADE + ); + """) + fresh_db["authors"].insert({"id": 1, "name": "Ursula K. Le Guin"}) + fresh_db["books"].insert({"id": 1, "title": "The Dispossessed", "author_id": 1}) + # Transform the table on the other end of the cascading foreign key + fresh_db["authors"].transform(rename={"name": "author_name"}) + assert list(fresh_db["authors"].rows) == [ + {"id": 1, "author_name": "Ursula K. Le Guin"} + ] + assert list(fresh_db["books"].rows) == [ + {"id": 1, "title": "The Dispossessed", "author_id": 1} + ] + # Transforming the table with the cascading foreign key should not + # delete its records either + fresh_db["books"].transform(rename={"title": "book_title"}) + assert list(fresh_db["books"].rows) == [ + {"id": 1, "book_title": "The Dispossessed", "author_id": 1} + ] + if use_pragma_foreign_keys: + assert fresh_db.conn.execute("PRAGMA foreign_keys").fetchone()[0] + + def test_transform_add_foreign_keys_from_scratch(fresh_db): _add_country_city_continent(fresh_db) fresh_db["places"].insert(_CAVEAU)