CREATE TABLE "singles_18_5_13" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent" text,
  "score" text
);

Question: When was naomi cavaday the opponent?
SQL: SELECT "date" FROM "singles_18_5_13" WHERE "opponent"='naomi cavaday';

Question: When was andrea gámiz the opponent?
SQL: SELECT "date" FROM "singles_18_5_13" WHERE "opponent"='andrea gámiz';

Question: Who is the opponent when the score was 6–4, 6–2 and the surface was clay?
SQL: SELECT "opponent" FROM "singles_18_5_13" WHERE "score"='6–4, 6–2' AND "surface"='clay';