Fixed #28365 -- Unified DatabaseOperations.date_interval_sql() return value with similar methods.

django/db/backends/mysql/operations.py

@@ -96,7 +96,7 @@ class DatabaseOperations(BaseDatabaseOperations):
             return "TIME(%s)" % (field_name)
 
     def date_interval_sql(self, timedelta):
-        return "INTERVAL '%06f' SECOND_MICROSECOND" % (timedelta.total_seconds()), []
+        return "INTERVAL '%06f' SECOND_MICROSECOND" % timedelta.total_seconds()
 
     def format_for_duration_arithmetic(self, sql):
         if self.connection.features.supports_microsecond_precision:

django/db/backends/oracle/operations.py

@@ -77,7 +77,7 @@ END;
         """
         NUMTODSINTERVAL converts number to INTERVAL DAY TO SECOND literal.
         """
-        return "NUMTODSINTERVAL(%06f, 'SECOND')" % (timedelta.total_seconds()), []
+        return "NUMTODSINTERVAL(%06f, 'SECOND')" % timedelta.total_seconds()
 
     def date_trunc_sql(self, lookup_type, field_name):
         # https://docs.oracle.com/database/121/SQLRF/functions271.htm#SQLRF52058

django/db/backends/sqlite3/operations.py

@@ -54,7 +54,7 @@ class DatabaseOperations(BaseDatabaseOperations):
         return "django_date_extract('%s', %s)" % (lookup_type.lower(), field_name)
 
     def date_interval_sql(self, timedelta):
-        return "'%s'" % duration_string(timedelta), []
+        return "'%s'" % duration_string(timedelta)
 
     def format_for_duration_arithmetic(self, sql):
         """Do nothing since formatting is handled in the custom function."""

django/db/models/expressions.py

@@ -639,7 +639,7 @@ class DurationValue(Value):
         connection.ops.check_expression_support(self)
         if connection.features.has_native_duration_field:
             return super().as_sql(compiler, connection)
-        return connection.ops.date_interval_sql(self.value)
+        return connection.ops.date_interval_sql(self.value), []
 
 
 class RawSQL(Expression):

docs/releases/2.0.txt

@@ -323,9 +323,10 @@ This section describes changes that may be needed in third-party database
 backends.
 
 * The ``DatabaseOperations.datetime_cast_date_sql()``,
-  ``datetime_cast_time_sql()``, ``datetime_trunc_sql()``, and
-  ``datetime_extract_sql()`` methods now return only the SQL to perform the
-  operation instead of SQL and a list of parameters.
+  ``datetime_cast_time_sql()``, ``datetime_trunc_sql()``,
+  ``datetime_extract_sql()``, and ``date_interval_sql()`` methods now return
+  only the SQL to perform the operation instead of SQL and a list of
+  parameters.
 
 * Third-party database backends should add a ``DatabaseWrapper.display_name``
   attribute with the name of the database that your backend works with. Django