What's the Issue Date for an Eric Prydz song with a no available Download information?
CREATE TABLE "singles_chart" (
  "week" real,
  "issue_date" text,
  "artist" text,
  "single" text,
  "download" text,
  "title" text
);
SELECT "issue_date" FROM "singles_chart" WHERE "download"='no available' AND "artist"='eric prydz';