CREATE TABLE table_29436238_1 (no_in_series VARCHAR2, written_by VARCHAR2)

How many episodes were written by Gregg Mettler?
SELECT COUNT(no_in_series) FROM table_29436238_1 WHERE written_by = "Gregg Mettler"
SELECT COUNT("no_in_series") FROM "table_29436238_1" WHERE "Gregg Mettler" = "written_by"