class Cql::Relations::Collection(Target, Pk)

• Cql::Relations::Collection(Target, Pk)
• Reference
• Object

Overview

A collection of records for a one to many relationship This class is used to manage the relationship between two tables through a foreign key column in the target table and provide methods to manage the association between the two tables and query records in the associated table based on the foreign key value of the parent record.

• param : Target (Cql::Model) - The target model
• param : Pk (Int64) - The primary key type
• return : Nil

Example

class User
  include Cql::Model(User, Int64)
  property id : Int64
  property name : String
  has_many :posts, Post, foreign_key: :user_id
end

Direct Known Subclasses

• Cql::Relations::ManyCollection(Target, Through, Pk)

Defined in:

Constructors

• .new(key : Symbol, id : Pk, cascade : Bool = false, query : Cql::Query = (Cql::Query.new(Target.schema)).from(Target.table))

  Initialize the many-to-many association collection class - param : key (Symbol) - The key for the parent record - param : id (Pk) - The id value for the parent record - param : target_key (Symbol) - The key for the associated record - param : cascade (Bool) - Delete associated records - param : query (Cql::Query) - Query object - return : ManyCollection

Macro Summary

• method_missing(call)

Instance Method Summary

• #<<(record : Target)

  Create a new record and associate it with the parent record if it doesn't exist - param : record (Target) - return : Array(Target)

• #all : Array(Target)

  Create a new record and associate it with the parent record - return : Array(Target)

• #clear

  Clears all associated records from the parent record and the database - return : [] of T

• #create(record : Target)

  Create a new record and associate it with the parent record - param : attributes (Hash(Symbol, String | Int64)) - return : Array(Target) - raise : Cql::Error

• #create(**attributes)

  Create a new record and associate it with the parent record - param : attributes (Hash(Symbol, String | Int64)) - return : Array(Target) - raise : Cql::Error

• #delete(record : Target)

  Delete the associated record from the parent record if it exists - param : record (Target) - return : Bool

• #delete(id : Pk)

  Delete the associated record from the parent record if it exists - param : id (Pk) - return : Bool

• #empty?

  Check if the association is empty or not - return : Bool

• #exists?(**attributes)

  Check if the association exists or not based on the attributes provided - param : attributes (Hash(Symbol, String | Int64)) - return : Bool

• #find(**attributes)

  Find associated records based on the attributes provided for the parent record - param : attributes (Hash(Symbol, String | Int64)) - return : Array(Target)

• #ids : Array(Pk)

  Returns a list if primary keys for the associated records - return : Array(Pk)

• #ids=(ids : Array(Pk))

  Associates the parent record with the records that match the primary keys provided - param : ids (Array(Pk)) - return : Array(Target)

• #reload

  Reload the association records from the database and return them - return : Array(Target)

• #size

  Returns the number of associated records for the parent record - return : Int64

Constructor Detail

ManyCollection.new(
  :movie_id,
  1,
  :actor_id,
  false,
  Cql::Query.new(Actor.schema).from(Actor.table)
)

Macro Detail

Instance Method Detail

movie.actors << Actor.new(name: "Laurence Fishburne")
movie.actors.reload
movie.actors.all
=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Laurence Fishburne">]

movie.actors.all
movie.actors.create(name: "Carrie-Anne Moss")
movie.actors.reload

=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Carrie-Anne Moss">]

movie.actors.create(name: "Carrie-Anne Moss")
movie.actors.reload
movie.actors.all => 1
movie.actors.clear
movie.actors.reload
movie.actors.all => []

movie.actors.create!(name: "Hugo Weaving")
movie.actors.reload
movie.actors.all
=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Hugo Weaving">]

movie.actors.create(name: "Carrie-Anne Moss")
movie.actors.reload
movie.actors.all
=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Carrie-Anne Moss">]

movie.actors.create(name: "Carrie-Anne Moss")
movie.actors.reload
movie.actors.all => 1

movie.actors.delete(Actor.find(1))
movie.actors.reload
movie.actors.all

=> [] of Actor

movie.actors.create(name: "Carrie-Anne Moss")
movie.actors.reload
movie.actors.all => 1
movie.actors.delete(1)
movie.actors.reload
movie.actors.all => []

movie.actors.empty?
=> true

movie.actors.exists?(name: "Keanu Reeves")
=> true

movie.actors.find(name: "Keanu Reeves")
=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Keanu Reeves">]

movie.actors.ids
=> [1, 2, 3]

movie.actors.ids = [1, 2, 3]
movie.actors.reload
movie.actors.all => [
#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Carrie-Anne Moss">,
   #<Actor:0x00007f8b3b1b3f00 @id=2, @name="Hugo Weaving">,
  #<Actor:0x00007f8b3b1b3f00 @id=3, @name="Laurence Fishburne">]

movie.actors.reload
=> [#<Actor:0x00007f8b3b1b3f00 @id=1, @name="Carrie-Anne Moss">]

movie.actors.size
=> 1