Who directed episode 21?
CREATE TABLE table_23958944_5 (directed_by VARCHAR, no_by_season VARCHAR)
SELECT directed_by FROM table_23958944_5 WHERE no_by_season = 21
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_23958944_5 (directed_by VARCHAR, no_by_season VARCHAR) Question: Who directed episode 21? [/INST] SELECT directed_by FROM table_23958944_5 WHERE no_by_season = 21 </s>