How many doubles champions were there for the Serbia f6 Futures tournament?
CREATE TABLE table_11900378_1 (doubles_champions VARCHAR, tournament VARCHAR)
SELECT COUNT(doubles_champions) FROM table_11900378_1 WHERE tournament = "Serbia F6 Futures"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_11900378_1 (doubles_champions VARCHAR, tournament VARCHAR) Question: How many doubles champions were there for the Serbia f6 Futures tournament? [/INST] SELECT COUNT(doubles_champions) FROM table_11900378_1 WHERE tournament = "Serbia F6 Futures" </s>