1
我的項目中有幾個型號。其中有一些是：Qualification和Curriculum。 Qualification有孩子（課程表）。我想確保當我刪除Qualification我刪除了所有的孩子。這裏是我的代碼：Rails 3 - 依賴=>：delete_all不起作用。爲什麼？
# Table name: qualifications
#
# id :integer not null, primary key
# subject_id :integer
# teacher_id :integer
# created_at :datetime not null
# updated_at :datetime not null
class Qualification < ActiveRecord::Base
belongs_to :subject
belongs_to :teacher
has_many :curriculums, :dependent => :delete_all
has_many :school_classes, :through => :curriculums
end
# id :integer not null, primary key
# school_class_id :integer
# qualification_id :integer
# created_at :datetime not null
# updated_at :datetime not null
class Curriculum < ActiveRecord::Base
belongs_to :school_class
belongs_to :qualification
has_one :result
has_many :timetables
end
正如你所看到的，我試圖在資格模型中使用:dependent => :delete_all。但它不起作用。爲什麼？
UPD：
我在視圖中取消選中複選框刪除資格當我編輯：
<div class="control-group">
<%= f.label :subject_ids, "Teacher can teach such subjects in the school",
:class => "control-label" %>
<div class="controls">
<table class="table table-bordered table-striped">
<thead>
<tr>
<th>Choose</th>
<th>Subject</th>
</tr>
</thead>
<tbody>
<%= hidden_field_tag "teacher[subject_ids][]", nil %> <%# We use hidden field because it doesn't submit unchecked fields. So, we pass nil and nothing will be submitted.%>
<% @subjects.each do |subject| %>
<tr>
<td>
<%= check_box_tag "teacher[subject_ids][]", # [] brackets tells that this is array.
subject.id, # Value of checkbox.
@teacher.subject_ids.include?(subject.id), # Here we automatically check checkboxes.
id: dom_id(subject) %> <%# Give unique id for each value. 'dom_id' is Rails helper. We will have ids like: 'subject_1', 'subject_2' and etc. %>
</td>
<td>
<%= label_tag dom_id(subject), subject.subject_name %> <%# Put name of subject. %>
</td>
</tr>
<% end %>
</tbody>
</table>
</div>
</div>
下面是詳細信息：
class Teacher < ActiveRecord::Base
has_many :qualifications
has_many :subjects, :through => :qualifications
end
class Subject < ActiveRecord::Base
has_many :qualifications
has_many :teachers, :through => :qualifications
end
下面是SQL代碼時，我更新我的模型：
Started PUT "/teachers/2" for 127.0.0.1 at 2012-06-03 18:34:44 +0400
Processing by TeachersController#update as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"ZJNNV9/TO6k18O1Ar1kpkU+PWbd7btHm9Tc067iMNO4=", "teacher"=>{"teacher_last_name"=>"Last", "teacher_first_name"=>"First", "teacher_middle_name"=>"Middle", "teacher_sex"=>"m", "teacher_birthday"=>"1980-12-01", "teacher_phone_attributes"=>{"teacher_mobile_number"=>"88283686", "teacher_home_number"=>"5112787", "id"=>"2"}, "teacher_education_attributes"=>{"teacher_education_university"=>"Mmm", "teacher_education_year"=>"1970-01-01", "teacher_education_graduation"=>"Graduated", "teacher_education_speciality"=>"Math", "id"=>"2"}, "teacher_category"=>"1st", "subject_ids"=>["", "4", "3", "1"]}, "commit"=>"Update", "id"=>"2"}
User Load (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = 2 LIMIT 1
Teacher Load (0.4ms) SELECT "teachers".* FROM "teachers" WHERE "teachers"."id" = $1 LIMIT 1 [["id", "2"]]
(0.1ms) BEGIN
Subject Load (0.5ms) SELECT "subjects".* FROM "subjects" WHERE "subjects"."id" IN (4, 3, 1)
Subject Load (0.5ms) SELECT "subjects".* FROM "subjects" INNER JOIN "qualifications" ON "subjects"."id" = "qualifications"."subject_id" WHERE "qualifications"."teacher_id" = 2
SQL (0.4ms) DELETE FROM "qualifications" WHERE "qualifications"."teacher_id" = 2 AND "qualifications"."subject_id" = 2
TeacherPhone Load (0.4ms) SELECT "teacher_phones".* FROM "teacher_phones" WHERE "teacher_phones"."teacher_id" = 2 LIMIT 1
TeacherEducation Load (0.4ms) SELECT "teacher_educations".* FROM "teacher_educations" WHERE "teacher_educations"."teacher_id" = 2 LIMIT 1
(24.1ms) COMMIT
Redirected to http://0.0.0.0:3000/teachers
Completed 302 Found in 57ms (ActiveRecord: 27.2ms)
你如何刪除資格。 –
我更新了我的問題。 – ExiRe