CREATE TABLE "administration" (
  "english_name" text,
  "simplified" text,
  "traditional" text,
  "pinyin" text,
  "hakka" text,
  "area" real,
  "population" real,
  "density" real
);

Question: What's the sum of the population for the place simplified 上杭县 with an area smaller than 2,879?
SQL: SELECT SUM("population") FROM "administration" WHERE "simplified"='上杭县' AND "area"<'2,879';

Question: What's the total number of density for the place with a population over 393,390?
SQL: SELECT COUNT("density") FROM "administration" WHERE "population">'393,390';

Question: What's the average area for the xinluo district?
SQL: SELECT AVG("area") FROM "administration" WHERE "english_name"='xinluo district';