CREATE TABLE wedding (name VARCHAR2, age VARCHAR2, is_male VARCHAR2, people_id VARCHAR2, male_id VARCHAR2)
CREATE TABLE people (name VARCHAR2, age VARCHAR2, is_male VARCHAR2, people_id VARCHAR2, male_id VARCHAR2)

Show the name and age for all male people who don't have a wedding.
SELECT name, age FROM people WHERE is_male = 'T' AND NOT people_id IN (SELECT male_id FROM wedding)
SELECT "name", "age" FROM "people" WHERE "is_male" = 'T' AND NOT "people_id" IN (SELECT "male_id" FROM "wedding")