Fixed #34799 -- Made MySQL introspection skip cross-database relations.

1 files changed, 60 insertions, 0 deletions

diff --git a/tests/backends/mysql/test_introspection.py b/tests/backends/mysql/test_introspection.py
index c1247de232..a2e2938451 100644
--- a/tests/backends/mysql/test_introspection.py
+++ b/tests/backends/mysql/test_introspection.py
@@ -61,3 +61,63 @@ class StorageEngineTests(TestCase):
                 cursor.execute(drop_sql)
             with other_connection.cursor() as cursor:
                 cursor.execute(drop_sql)
+
+
+@skipUnless(connection.vendor == "mysql", "MySQL specific SQL")
+class TestCrossDatabaseRelations(TestCase):
+    databases = {"default", "other"}
+
+    def test_omit_cross_database_relations(self):
+        default_connection = connections["default"]
+        other_connection = connections["other"]
+        main_table = "cross_schema_get_relations_main_table"
+        main_table_quoted = default_connection.ops.quote_name(main_table)
+        other_schema_quoted = other_connection.ops.quote_name(
+            other_connection.settings_dict["NAME"]
+        )
+        rel_table = "cross_schema_get_relations_rel_table"
+        rel_table_quoted = other_connection.ops.quote_name(rel_table)
+        rel_column = "cross_schema_get_relations_rel_table_id"
+        rel_column_quoted = other_connection.ops.quote_name(rel_column)
+        try:
+            with other_connection.cursor() as other_cursor:
+                other_cursor.execute(
+                    f"""
+                    CREATE TABLE {rel_table_quoted} (
+                        id integer AUTO_INCREMENT,
+                        PRIMARY KEY (id)
+                    )
+                    """
+                )
+            with default_connection.cursor() as default_cursor:
+                # Create table in the default schema with a cross-database
+                # relation.
+                default_cursor.execute(
+                    f"""
+                    CREATE TABLE {main_table_quoted} (
+                        id integer AUTO_INCREMENT,
+                        {rel_column_quoted} integer NOT NULL,
+                        PRIMARY KEY (id),
+                        FOREIGN KEY ({rel_column_quoted})
+                        REFERENCES {other_schema_quoted}.{rel_table_quoted}(id)
+                    )
+                    """
+                )
+                relations = default_connection.introspection.get_relations(
+                    default_cursor, main_table
+                )
+                constraints = default_connection.introspection.get_constraints(
+                    default_cursor, main_table
+                )
+            self.assertEqual(len(relations), 0)
+            rel_column_fk_constraints = [
+                spec
+                for name, spec in constraints.items()
+                if spec["columns"] == [rel_column] and spec["foreign_key"] is not None
+            ]
+            self.assertEqual(len(rel_column_fk_constraints), 0)
+        finally:
+            with default_connection.cursor() as default_cursor:
+                default_cursor.execute(f"DROP TABLE IF EXISTS {main_table_quoted}")
+            with other_connection.cursor() as other_cursor:
+                other_cursor.execute(f"DROP TABLE IF EXISTS {rel_table_quoted}")