Remove SET NAMES usage which is no-op in SingleStore

Author: pmishchenko-ua

singlestoredb/mysql/connection.py

@@ -997,9 +997,9 @@ def set_character_set(self, charset, collation=None):
         encoding = charset_by_name(charset).encoding
 
         if collation:
-            query = f'SET NAMES {charset} COLLATE {collation}'
+            query = f'SET COLLATION_CONNECTION {collation}'
         else:
-            query = f'SET NAMES {charset}'
+            query = f'SET CHARACTER_SET_SERVER {charset}'
         self._execute_command(COMMAND.COM_QUERY, query)
         self._read_packet()
         self.charset = charset