CREATE TABLE table_31212 ("Episode" CLOB, "Theme / Date" CLOB, "Song title" CLOB, "Original performer" CLOB, "Result  ( Placement ) " CLOB)

What is the episode when the original performaer is diana ross?
SELECT "Episode" FROM table_31212 WHERE "Original performer" = 'Diana Ross'
SELECT "Episode" FROM "table_31212" WHERE "Original performer" = 'Diana Ross'