CREATE TABLE "singles" (
  "tournament" text,
  "2006" text,
  "2007" text,
  "2008" text,
  "2009" text,
  "2010" text,
  "2011" text,
  "2012" text,
  "2013" text
);

Question: Which tournament has a value of a for 2009?
SQL: SELECT "tournament" FROM "singles" WHERE "2009"='a';

Question: What is the value for 2011 when `a` is the value for 2009, and 4r is the value for 2013?
SQL: SELECT "2011" FROM "singles" WHERE "2009"='a' AND "2013"='4r';