Context: CREATE TABLE countrylanguage (countrycode VARCHAR, language VARCHAR); CREATE TABLE country (name VARCHAR, code VARCHAR)
Question: What are the countries where either English or Dutch is the official language ?
Answer: SELECT t1.name FROM country AS t1 JOIN countrylanguage AS t2 ON t1.code = t2.countrycode WHERE t2.language = "english" AND isofficial = "t" UNION SELECT t1.name FROM country AS t1 JOIN countrylanguage AS t2 ON t1.code = t2.countrycode WHERE t2.language = "dutch" AND isofficial = "t"