CREATE TABLE table_12308 ("Res." CLOB, "Record" CLOB, "Opponent" CLOB, "Method" CLOB, "Event" CLOB, "Round" FLOAT, "Time" CLOB, "Location" CLOB)

Which opponent has a record of 3 1?
SELECT "Opponent" FROM table_12308 WHERE "Record" = '3–1'
SELECT "Opponent" FROM "table_12308" WHERE "Record" = '3–1'