Which Right ascension (J2000) has a Constellation of mensa, and an NGC number larger than 2171?
CREATE TABLE "2101_2200" (
  "ngc_number" real,
  "object_type" text,
  "constellation" text,
  "right_ascension_j2000" text,
  "declination_j2000" text
);
SELECT "right_ascension_j2000" FROM "2101_2200" WHERE "constellation"='mensa' AND "ngc_number">2171;