Question

I am trying to create a symfony2 application. The main idea behind the project is that there is an event which many guests are invited to and they are categorized. I have created a relational model for all the entities.

There are 4 tables:

1. Guests – who is invited
2. Category – what category/categories he belongs to ?
3. Event – the event which they are invited to
4. Guest_Event (attendance)

I have concluded to the following schemas:

xxxxBundle\Entity\Guest:
  type: entity
  table: guest
  id:
    id:
      type: integer
      generator: { strategy: AUTO }
  fields:
    name:
      type: string
      length: 100
      nullable: false
    surname:
      type: string
      length: 100
      nullable: false   
    email:
      type: string
      length: 255
      nullable: true
    address:
      type: string
      length: 255
      nullable: true
    phone:
      type: string
      length: 10
    description:
      type: text
    created_at:
      type: datetime
    updated_at:
      type: datetime
      nullable: true   
    token:
      type: string
      length: 255
      unique: true
    is_activated:
      type: boolean
      nullable: true
  manyToOne:
    category:
      targetEntity: Category
      inversedBy: guest
      joinColumn:
        name: category_id
        referencedColumnName: id
  lifecycleCallbacks:
    prePersist: [ setCreatedAtValue ]
    preUpdate: [ setUpdatedAtValue ]

Category

xxxxBundle\Entity\Category:
  type: entity
  table: category
  id:
    id:
      type: integer
      generator: { strategy: AUTO }
  fields:
    name:
      type: string
      length: 255
      unique: true
  oneToMany:
    guests:
      targetEntity: Guest
      mappedBy: category
    attend:
      targetEntity: Attendance
      mappedBy: category

Event

xxxxxBundle\Entity\Event:
  type: entity
  table: event
  id:
    id:
      type: integer
      generator: { strategy: AUTO }
  fields:
    name:
      type: string
      length: 100
      nullable: false
    location:
      type: string
      length: 255
      nullable: true
    scheduled_at:
      type: datetime
  manyToMany:
    category:
      targetEntity: guest
      inversedBy: event
      joinColumn:
        name: event_id
        referencedColumnName: id

• A guest might belong to multiple categories (manyToOne)
• A category will have many guests (manyToOne)
• A guest might attend many events (manyToOne)
• An event might have many attendants (manyToMany?)
• the attendance table (guest_event) should be a join table ?

I am a little bit confused about ORM and doctrine coding. Creating the tables via SQL code or phpmyadmin seems much easier to me but I want to go the hard way ! The documentation seems confusing because each tutorial suggests different things and the doctrine ORM section in the symfony2 book doesn’t have a complete example but pieces of code..

How can I correct my tables to include all the specifications ?

Answer 1

My two cents:

A guest might belong to multiple categories

So many guests can belong to many categories, so it’s many to many guest side. Assuming the owning side is Guest:

xxxxBundle\Entity\Guest:
  manyToMany:
    categories:
      targetEntity: Category
      inversedBy: guests
      joinTable:
         name: guests_categories

A category will have many guests (manyToOne)

If category will have many guests, why is’s many to one? Many categories can be assigned to many guest:

xxxxBundle\Entity\Category:
  manyToMany:
    guests:
      targetEntity: Guest
      mappedBy: categories

If i understand you correctly, a categoy may exist even without a guest, and vice-versa a guest may exist even without a category.

And for guest/events relation, i’ll go again for many to many / many to many. Take a look at here and ask yourself: one/many type of my entity can have one/many type of another entity?