CREATE TABLE people (name VARCHAR2, sex VARCHAR2, people_id VARCHAR2)
CREATE TABLE candidate (people_id VARCHAR2)

Find the name of the candidates whose oppose percentage is the lowest for each sex.
SELECT t1.name, t1.sex, MIN(oppose_rate) FROM people AS t1 JOIN candidate AS t2 ON t1.people_id = t2.people_id GROUP BY t1.sex
SELECT "t1"."name", "t1"."sex", MIN("oppose_rate") FROM "people" "t1" JOIN "candidate" "t2" ON "t1"."people_id" = "t2"."people_id" GROUP BY "t1"."sex"