CREATE TABLE table_203_539 (id NUMBER, "year" NUMBER, "competition" CLOB, "venue" CLOB, "position" CLOB, "event" CLOB, "notes" NUMBER)

which competition was shi dongpeng in before the world junior championships ?
SELECT "competition" FROM table_203_539 WHERE "year" < (SELECT "year" FROM table_203_539 WHERE "competition" = 'world junior championships') ORDER BY "year" LIMIT 1
SELECT "competition" FROM "table_203_539" WHERE "year" < (SELECT "year" FROM "table_203_539" WHERE "competition" = 'world junior championships') ORDER BY "year" FETCH FIRST 1 ROWS ONLY