SQL，Rails：检查记录中的JSONB列是否具有键值对

Question

No, this is just an example not a dating app for pets. My app is different and more complex.

I have a rails app. I have 2 tables House and Pet. A House has many Pet. My Pet table has a JSONB column called pet_description that contains a key value pairs of pet type and gender like so:

{ 
  "dog"=>"male", 
  "cat"=>"female", 
  "parrot"=>"male"
}

And the migration file for this is:

class AddPetDescriptionToPets < ActiveRecord::Migration
  def change
    add_column :pets, :pet_description, :jsonb, default: {}
    add_index  :pets, :pet_description, using: :gin
  end
end

In my House model, I have a query that executes a SQL query. It works if I do this query to find all houses that have pets.

self.where("EXISTS ( SELECT null FROM pets WHERE pets.house_id = houses.id)")

However if I want to query all houses that have a particular pet type and gender then I can't seem to get this query working. I am new to JSONB, what am I doing wrong in the query below?, please help!!!!

self.where("EXISTS ( SELECT null FROM pets WHERE pets.house_id = houses.id AND pets.pet_description @> '{'dog' : 'male'}'::jsonb)")

thanks! Greg

Answer 1

You may try to use different quotes symbols:

self.where("EXISTS ( 
  SELECT null 
  FROM pets 
  WHERE pets.house_id = houses.id 
    AND pets.pet_description @> '{\"dog\" : \"male\"}'::jsonb)")

Or let Rails take care about params formatting:

self.where("EXISTS ( 
  SELECT null 
  FROM pets 
  WHERE pets.house_id = houses.id 
    AND pets.pet_description @> ?)", {dog: 'male'}.to_json)