Fixed #26950 -- Removed obsolete DatabaseOperations SQL methods.

Unused as of 2b039d9.

django/db/backends/base/operations.py

@@ -152,19 +152,6 @@ def distinct_sql(self, fields):
         else:
             return 'DISTINCT'
 
-    def drop_foreignkey_sql(self):
-        """
-        Returns the SQL command that drops a foreign key.
-        """
-        return "DROP CONSTRAINT"
-
-    def drop_sequence_sql(self, table):
-        """
-        Returns any SQL necessary to drop the sequence for the given table.
-        Returns None if no SQL is necessary.
-        """
-        return None
-
     def fetch_returned_insert_id(self, cursor):
         """
         Given a cursor object that has just performed an INSERT...RETURNING

django/db/backends/mysql/operations.py

@@ -97,9 +97,6 @@ def format_for_duration_arithmetic(self, sql):
         else:
             return 'INTERVAL FLOOR(%s / 1000000) SECOND' % sql
 
-    def drop_foreignkey_sql(self):
-        return "DROP FOREIGN KEY"
-
     def force_no_ordering(self):
         """
         "ORDER BY NULL" prevents MySQL from implicitly ordering by grouped

django/db/backends/oracle/operations.py

@@ -241,9 +241,6 @@ def convert_empty_values(self, value, expression, connection, context):
     def deferrable_sql(self):
         return " DEFERRABLE INITIALLY DEFERRED"
 
-    def drop_sequence_sql(self, table):
-        return "DROP SEQUENCE %s;" % self.quote_name(self._get_sequence_name(table))
-
     def fetch_returned_insert_id(self, cursor):
         return int(cursor._insert_id_var.getvalue())
 

django/db/backends/sqlite3/operations.py

@@ -108,9 +108,6 @@ def time_extract_sql(self, lookup_type, field_name):
         # cause a collision with a field name).
         return "django_time_extract('%s', %s)" % (lookup_type.lower(), field_name)
 
-    def drop_foreignkey_sql(self):
-        return ""
-
     def pk_default_value(self):
         return "NULL"