When dwhr-tv is the call sign how many station types are there?
CREATE TABLE table_23394920_1 (station_type VARCHAR, callsign VARCHAR)
SELECT COUNT(station_type) FROM table_23394920_1 WHERE callsign = "DWHR-TV"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_23394920_1 (station_type VARCHAR, callsign VARCHAR) Question: When dwhr-tv is the call sign how many station types are there? [/INST] SELECT COUNT(station_type) FROM table_23394920_1 WHERE callsign = "DWHR-TV" </s>