CODEWITHSUNDEEP
ruby-on-railsactiverecord
Colton Seal
Colton Seal

Reputation: 379

To use a scope or not use a scope rails

I have two tables, People and Vehicles. Vehicles belongs to People.

I have a report/query that shows which people do not have a vehicle. Im trying to incorporate it into my rails app so that it runs when someone wants to see this information. I decided to write a scope for it, but cannot get the scope working properly. Code is below. Any ideas?

scope :person_has_no_vehicle, -> { joins(:vehicles).where('Vehicles.person_id IS NULL')}

Query is below

SELECT DISTINCT
    People.ID,
    People.nam_first,
    People.nam_last
FROM
    People
LEFT JOIN Vehicles ON People.ID = Vehicles.person_id
WHERE
    Vehicles.person_id IS NULL

Upvotes: 0

Views: 32

Answers (1)

Jiří Pospíšil
Jiří Pospíšil

Reputation: 14402

The joins method always performs an INNER JOIN, but your original SQL query uses LEFT JOIN.

scope :person_has_no_vehicle, -> { joins("LEFT OUTER JOIN vehicles ON vehicles.person_id = people.id").where('Vehicles.person_id IS NULL')}

Upvotes: 1

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