查询MySQL数据库以插入到特定记录中

I'm trying to insert data about a user on my website but I think the MySQL query I'm using is invalid. I want to insert the value '$profile' into the 'pph_user_bio' column inside the 'pph_user_profile' table however inside that table is a foreign key linking back to a table named 'users' which stores the user's '_id' so I only want the database to insert the data ($profile) into the corresponding '_id' which is set as the current session id.I'm trying to insert data about a user on my we