I have 2 models as describes below.
class EmpGroup < ActiveRecord::Base belongs_to :user has_many :emp_group_members, dependent: :destroy end and
class EmpGroupMember < ActiveRecord::Base belongs_to :emp_group belongs_to :user end now the problem is whenever I tried to destroy a group then I received a error as below.
PG::ForeignKeyViolation: ERROR: update or delete on table "emp_groups" violates foreign key constraint "fk_rails_bd68440021" on table "emp_group_members" DETAIL: Key (id)=(1) is still referenced from table "emp_group_members". What I'm missing?
5 Answers
Add cascading delete to your EmpGroup model:
class EmpGroup < ActiveRecord::Base has_many :emp_group_members, dependent: :delete_all end Or
Are you calling delete method? you should call destroy instead. Use .destroy
:dependent is one of the options available in belongs_to association
If you set the :dependent option to: :destroy, when the object is destroyed, destroy will be called on its associated objects. :delete, when the object is destroyed, all its associated objects will be deleted directly from the database without calling their destroy method. Additionally, objects will be destroyed if they're associated with dependent: :destroy, and deleted if they're associated with dependent: :delete_all.
in has_many associations:
:destroy causes all the associated objects to also be destroyed :delete_all causes all the associated objects to be deleted directly from the database (so callbacks will not execute) you can try
emp_member_1= @emp_group.emp_group_members.first ##delete associated record @emp_group.emp_group_members.delete(emp_member_1) New syntax:
class EmpGroup < ActiveRecord::Base has_many :emp_group_members, dependent: :destroy end When you delete a group, are you using delete or destroy. - I've had this error before, and it was because I had a typo and was using .delete instead of .destroy
Insert relation like this
has_many :children, :dependent => :destroy 
