What is the production code of the episode directed by David Solomon? 
CREATE TABLE table_21304155_1 (production_code VARCHAR, directed_by VARCHAR)
SELECT production_code FROM table_21304155_1 WHERE directed_by = "David Solomon"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21304155_1 (production_code VARCHAR, directed_by VARCHAR) Question: What is the production code of the episode directed by David Solomon?  [/INST] SELECT production_code FROM table_21304155_1 WHERE directed_by = "David Solomon" </s>