import unittest

from django.db import connection

from django.test import TransactionTestCase

from ..models import Square

@unittest.skipUnless(connection.vendor == "oracle", "Oracle tests")

class DatabaseSequenceTests(TransactionTestCase):

    available_apps = []

    def test_get_sequences(self):

        with connection.cursor() as cursor:

            seqs = connection.introspection.get_sequences(

                cursor, Square._meta.db_table, Square._meta.local_fields

            )

            self.assertEqual(len(seqs), 1)

            self.assertIsNotNone(seqs[0]["name"])

            self.assertEqual(seqs[0]["table"], Square._meta.db_table)

            self.assertEqual(seqs[0]["column"], "id")

    def test_get_sequences_manually_created_index(self):

        with connection.cursor() as cursor:

            with connection.schema_editor() as editor:

                editor._drop_identity(Square._meta.db_table, "id")

                seqs = connection.introspection.get_sequences(

                    cursor, Square._meta.db_table, Square._meta.local_fields

                )

                self.assertEqual(

                    seqs, [{"table": Square._meta.db_table, "column": "id"}]

                )

                # Recreate model, because adding identity is impossible.

                editor.delete_model(Square)

                editor.create_model(Square)