Fixed #29444 -- Allowed returning multiple fields from INSERT statements on Oracle.

django/db/backends/base/operations.py

@@ -176,7 +176,7 @@ class BaseDatabaseOperations:
         else:
             return ['DISTINCT'], []
 
-    def fetch_returned_insert_columns(self, cursor):
+    def fetch_returned_insert_columns(self, cursor, returning_params):
         """
         Given a cursor object that has just performed an INSERT...RETURNING
         statement into a table, return the newly created data.

django/db/backends/oracle/features.py

@@ -10,6 +10,7 @@ class DatabaseFeatures(BaseDatabaseFeatures):
     has_select_for_update_of = True
     select_for_update_of_column = True
     can_return_columns_from_insert = True
+    can_return_multiple_columns_from_insert = True
     can_introspect_autofield = True
     supports_subqueries_in_group_by = False
     supports_transactions = True

django/db/backends/oracle/operations.py

@@ -248,17 +248,19 @@ END;
     def deferrable_sql(self):
         return " DEFERRABLE INITIALLY DEFERRED"
 
-    def fetch_returned_insert_columns(self, cursor):
-        value = cursor._insert_id_var.getvalue()
+    def fetch_returned_insert_columns(self, cursor, returning_params):
+        for param in returning_params:
+            value = param.get_value()
             if value is None or value == []:
                 # cx_Oracle < 6.3 returns None, >= 6.3 returns empty list.
                 raise DatabaseError(
-                'The database did not return a new row id. Probably "ORA-1403: '
-                'no data found" was raised internally but was hidden by the '
-                'Oracle OCI library (see https://code.djangoproject.com/ticket/28859).'
+                    'The database did not return a new row id. Probably '
+                    '"ORA-1403: no data found" was raised internally but was '
+                    'hidden by the Oracle OCI library (see '
+                    'https://code.djangoproject.com/ticket/28859).'
                 )
             # cx_Oracle < 7 returns value, >= 7 returns list with single value.
-        return value if isinstance(value, list) else [value]
+            yield value[0] if isinstance(value, list) else value
 
     def field_cast_sql(self, db_type, internal_type):
         if db_type and db_type.endswith('LOB'):
@@ -344,11 +346,18 @@ END;
     def return_insert_columns(self, fields):
         if not fields:
             return '', ()
-        sql = 'RETURNING %s.%s INTO %%s' % (
-            self.quote_name(fields[0].model._meta.db_table),
-            self.quote_name(fields[0].column),
-        )
-        return sql, (InsertVar(fields[0]),)
+        field_names = []
+        params = []
+        for field in fields:
+            field_names.append('%s.%s' % (
+                self.quote_name(field.model._meta.db_table),
+                self.quote_name(field.column),
+            ))
+            params.append(InsertVar(field))
+        return 'RETURNING %s INTO %s' % (
+            ', '.join(field_names),
+            ', '.join(['%s'] * len(params)),
+        ), tuple(params)
 
     def __foreign_key_constraints(self, table_name, recursive):
         with self.connection.cursor() as cursor:

django/db/backends/oracle/utils.py

@@ -27,11 +27,14 @@ class InsertVar:
     def __init__(self, field):
         internal_type = getattr(field, 'target_field', field).get_internal_type()
         self.db_type = self.types.get(internal_type, str)
+        self.bound_param = None
 
     def bind_parameter(self, cursor):
-        param = cursor.cursor.var(self.db_type)
-        cursor._insert_id_var = param
-        return param
+        self.bound_param = cursor.cursor.var(self.db_type)
+        return self.bound_param
+
+    def get_value(self):
+        return self.bound_param.getvalue()
 
 
 class Oracle_datetime(datetime.datetime):

django/db/models/sql/compiler.py

@@ -1152,6 +1152,7 @@ class SQLCompiler:
 
 class SQLInsertCompiler(SQLCompiler):
     returning_fields = None
+    returning_params = tuple()
 
     def field_as_sql(self, field, val):
         """
@@ -1300,10 +1301,10 @@ class SQLInsertCompiler(SQLCompiler):
                 result.append(ignore_conflicts_suffix_sql)
             # Skip empty r_sql to allow subclasses to customize behavior for
             # 3rd party backends. Refs #19096.
-            r_sql, r_params = self.connection.ops.return_insert_columns(self.returning_fields)
+            r_sql, self.returning_params = self.connection.ops.return_insert_columns(self.returning_fields)
             if r_sql:
                 result.append(r_sql)
-                params += [r_params]
+                params += [self.returning_params]
             return [(" ".join(result), tuple(chain.from_iterable(params)))]
 
         if can_bulk:
@@ -1342,7 +1343,7 @@ class SQLInsertCompiler(SQLCompiler):
                         'not supported on this database backend.'
                     )
                 assert len(self.query.objs) == 1
-                return self.connection.ops.fetch_returned_insert_columns(cursor)
+                return self.connection.ops.fetch_returned_insert_columns(cursor, self.returning_params)
             return [self.connection.ops.last_insert_id(
                 cursor, self.query.get_meta().db_table, self.query.get_meta().pk.column
             )]

docs/releases/3.1.txt

@@ -208,7 +208,8 @@ Database backend API
 This section describes changes that may be needed in third-party database
 backends.
 
-* ...
+* ``DatabaseOperations.fetch_returned_insert_columns()`` now requires an
+  additional ``returning_params`` argument.
 
 Miscellaneous
 -------------