Who are the writers for the episode number in series 129?
CREATE TABLE table_21312959_1 (written_by VARCHAR, no_in_series VARCHAR)
SELECT written_by FROM table_21312959_1 WHERE no_in_series = 129
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21312959_1 (written_by VARCHAR, no_in_series VARCHAR) Question: Who are the writers for the episode number in series 129? [/INST] SELECT written_by FROM table_21312959_1 WHERE no_in_series = 129 </s>