Name who wrote the episode that aired april 9, 1989
CREATE TABLE table_2226817_4 (written_by VARCHAR, original_air_date VARCHAR)
SELECT written_by FROM table_2226817_4 WHERE original_air_date = "April 9, 1989"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_2226817_4 (written_by VARCHAR, original_air_date VARCHAR) Question: Name who wrote the episode that aired april 9, 1989 [/INST] SELECT written_by FROM table_2226817_4 WHERE original_air_date = "April 9, 1989" </s>