Module: Simple::SQL::Result::AssociationLoader

Extended by:
AssociationLoader
Included in:
AssociationLoader
Defined in:
lib/simple/sql/result/association_loader.rb

Overview

This module implements a pretty generic AssociationLoader.

Constant Summary collapse

SQL = 
::Simple::SQL
H = 
::Simple::SQL::Helpers

Instance Method Summary collapse

Instance Method Details

#preload(records, association, host_table:, schema:, as:, order_by:, limit:) ⇒ Object

Preloads a association into the records array.

Parameters:

  • records: an Array of hashes.

  • association: the name of the association

  • host_table: the name of the table a records has been loaded from.

  • schema: the schema name in the database.

  • as: the name to sue for the association. Defaults to association



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# File 'lib/simple/sql/result/association_loader.rb', line 151

def preload(records, association, host_table:, schema:, as:, order_by:, limit:)
  return records if records.empty?

  expect! records.first => Hash

  as = association if as.nil?
  fq_host_table = "#{schema}.#{host_table}"

  associated_table = find_associated_table(association, schema: schema)
  relation         = find_matching_relation(fq_host_table, associated_table)

  if fq_host_table == relation.belonging_table
    if order_by || limit
      raise ArgumentError, "#{association.inspect} is a singular association, w/o support for order_by: and limit:"
    end
    preload_belongs_to records, relation, as: as
  else
    preload_has_one_or_many records, relation, as: as, order_by: order_by, limit: limit
  end
end