Lead to Order Table design I have a User table having following fields:

id, name, phone, email


and an Order table:

id, order_name, order_desc, user_id (fk to User)


and a Lead table:

id, lead_desc, user_id (fk to User), lead_status


Now, I want to know for each lead (once the lead_status become closed), which order is created from this lead or no order is created from this lead. I am planning to have an order_id (with null=True) foreign key in Lead table to keep this mapping. But since Order table already have a user_id, it doesn't seem to be a good idea. 

Is there a better way to do it? I am using Mysql.
One of the of goals of a relational database is to eliminate double storage of data. If you can find the right User for the Lead through the Order then you can leave out the reference in one of the tables (they are always the same as you mentioned in a comment). Keeping it in both tables makes your application more complicated.