How many weeks featured duffy as the original artist?
CREATE TABLE table_21501564_1 (theme VARCHAR, original_artist VARCHAR)
SELECT COUNT(theme) FROM table_21501564_1 WHERE original_artist = "Duffy"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21501564_1 (theme VARCHAR, original_artist VARCHAR) Question: How many weeks featured duffy as the original artist? [/INST] SELECT COUNT(theme) FROM table_21501564_1 WHERE original_artist = "Duffy" </s>