Who was the partner when the championship was us open on a hard surface?
CREATE TABLE table_name_30 (partner VARCHAR, surface VARCHAR, championship VARCHAR)
SELECT partner FROM table_name_30 WHERE surface = "hard" AND championship = "us open"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_name_30 (partner VARCHAR, surface VARCHAR, championship VARCHAR) Question: Who was the partner when the championship was us open on a hard surface? [/INST] SELECT partner FROM table_name_30 WHERE surface = "hard" AND championship = "us open" </s>