CREATE TABLE "by_population" (
  "province" text,
  "population" real,
  "region" text,
  "name_of_city" text,
  "districts" real
);

Question: What is the region where Iquitos is located?
SQL: SELECT "region" FROM "by_population" WHERE "name_of_city"='Iquitos';

Question: What is the region containing the Constitutional Province of Callao?
SQL: SELECT "region" FROM "by_population" WHERE "province"='Constitutional Province of Callao';