I want to raise an exception or error when the associated record exists when deleting a record. This is a situation where the parent element should not be erased if it is used in a foreign key.
When I try to delete it, a Ruby error screen appears.
It was because there was no definition of the behavior for the model associated with Model.
The migration file foreign key: True was not enough.
It was solved by writing the dependent option in the Model.
Write the following for the model.
#Model called contract
class Contract < ApplicationRecord
has_many :...., dependent: :restrict_with_error
end
By writing dependent:: restrict_with_error after the association description, it was possible to display the error when destory cannot be done.
The following conditions have been met and resolved! ..
#Controller of model called contract
def destroy
contract = Contract.find(params[:id])
if contract.destroy
redirect_to contract_path, notice: "Deleted the selected contract"
else
redirect_to contract_path, alert: "Cannot be deleted because it is in use"
end
end
・ Https://dorarep.page/articles/rails-dependent#dependent_restrict_with_exception_restrict_with_error