I’d like to merge two queries in my rails app. Each one is not very complex but I can’t merge them.
owner_packages = Package.where(owner: current_user)
admins_packages = current_user.managed_packages
@managable_packages = owner_packages.or(admins_packages)
user.rb
has_many :package_admins, dependent: :destroy
has_many :managed_packages, through: :package_admins, source: :package
package.rb
has_many :package_admins, dependent: :destroy
has_many :admins, through: :package_admins, source: :user
I’m running into this error:
Relation passed to #or must be structurally compatible. Incompatible values: [:joins]
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Answer
I think what you’re looking for is a subselect:
owner_packages = Package.where(owner: current_user)
admins_packages = current_user.managed_packages
@managable_packages = owner_packages.or(Package.where(id: admins_packages))
This code should really be moved into the model instead of leaving all the wires hanging out:
class User < ApplicationRecord
has_many :owned_packages, class_name: 'Package',
foreign_key: :owner_id # just guessing here
has_many :package_admins, dependent: :destroy
has_many :managed_packages, through: :package_admins, source: :package
def managable_packages
owned_packages.or(Package.where(id: managed_packages))
end
end
An alternative method is using a union:
class User < ApplicationRecord
# ...
def managable_packages
Package.from(
owned_packages.arel.union(managed_packages.arel).as('packages')
)
end
end