CREATE TABLE "current_composition" (
  "affiliation" text,
  "life_peers" text,
  "hereditary_peers" text,
  "lords_spiritual" text,
  "total" real
);

Question: Which Hereditary peers have a Total of 1?
SQL: SELECT "hereditary_peers" FROM "current_composition" WHERE "total"=1;

Question: Which Total has a Hereditary peer of –, and a Lords spiritual of –, and a Life peers of 2, and an Affiliation of plaid cymru?
SQL: SELECT COUNT("total") FROM "current_composition" WHERE "hereditary_peers"='–' AND "lords_spiritual"='–' AND "life_peers"='2' AND "affiliation"='plaid cymru';