human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Name, Birth, Marriage, Became Dauphine, Ceased to be Dauphine, Death, Husband
###Question: when was the marriage when became dauphine is 31 august 1412?
gpt
SELECT Marriage FROM table WHERE Became Dauphine = 31 august 1412