CREATE TABLE table_203_537 (id NUMBER, "#" NUMBER, "date" CLOB, "venue" CLOB, "opponent" CLOB, "score" CLOB, "result" CLOB, "competition" CLOB)

list the opponents which are under the friendly competition .
SELECT "opponent" FROM table_203_537 WHERE "competition" = 'friendly'
SELECT "opponent" FROM "table_203_537" WHERE "competition" = 'friendly'