Which Works number has a Builder of avonside engine company, and a Type of 4-6-0, and a Number smaller than 12, and a Date of december 1871?
CREATE TABLE "locomotives" (
  "number" real,
  "builder" text,
  "type" text,
  "date" text,
  "works_number" text
);
SELECT "works_number" FROM "locomotives" WHERE "builder"='avonside engine company' AND "type"='4-6-0' AND "number"<12 AND "date"='december 1871';