I think we need to see one your kid/sport model and then the new/
create method in the controller...
You should not have a id column btw in the kids_sports table.. .
This should be your up task:
def self.up
create_table :kids_sports, :id => false do |t|
t.integer :kid_id
t.integer :sport_id
end
add_index :kids_sports, [:kid_id]
add_index :kids_sports, [:sport_id]
end
