user: Question: What is the callsign that has a station type of Relay and a channel number of TV-2?
Columns: ['Branding', 'Callsign', 'Ch. #', 'Power kW', 'Station Type', 'Location (Transmitter site)']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['PTV 4 Manila', 'DWGT-TV', 'TV-4', '50 kW (500 kW ERP)', 'Originating', 'Metro Manila']
SQL:

assistant: SELECT "Callsign" FROM "Table" WHERE "Station Type" = 'Relay' AND "Ch. #" = 'TV-2';