CREATE TABLE table_name_50 (date_from VARCHAR2, position VARCHAR2, name VARCHAR2)

What is the date for the MF position and player Jennison Myrie-Williams?
SELECT date_from FROM table_name_50 WHERE position = "mf" AND name = "jennison myrie-williams"
SELECT "date_from" FROM "table_name_50" WHERE "jennison myrie-williams" = "name" AND "mf" = "position"