CREATE TABLE table_28688 ("No. in series" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" FLOAT, "U.S. viewers  ( millions ) " CLOB)

How many different production codes are there for the episode with 4.69 million US viewers?
SELECT COUNT("Production code") FROM table_28688 WHERE "U.S. viewers (millions)" = '4.69'
SELECT COUNT("Production code") FROM "table_28688" WHERE "U.S. viewers (millions)" = '4.69'