| # official docs: https://graphql-ruby.org/dataloader/sources.html | |
| # app/graphql/sources/association.rb | |
| class Sources::Association < ::GraphQL::Dataloader::Source | |
| def initialize(association_name, scope = nil) | |
| @association_name = association_name | |
| @scope = scope | |
| end | |
| def fetch(records) |
| http://stackoverflow.com/questions/22667401/postgres-json-data-type-rails-query | |
| http://stackoverflow.com/questions/40702813/query-on-postgres-json-array-field-in-rails | |
| #payload: [{"kind"=>"person"}] | |
| Segment.where("payload @> ?", [{kind: "person"}].to_json) | |
| #data: {"interest"=>["music", "movies", "programming"]} | |
| Segment.where("data @> ?", {"interest": ["music", "movies", "programming"]}.to_json) | |
| Segment.where("data #>> '{interest, 1}' = 'movies' ") | |
| Segment.where("jsonb_array_length(data->'interest') > 1") |
FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.
This brief guide is written from my own experience with migrating a large (~5GB) MySQL database to PostgreSQL for a Rails project.
No warranties, guarantees, support etc. Use at your own risk and, as always, ENSURE YOU MAKE BACKUPS FIRST!
I chose [pgloader][1] because it's extremely fast. YMMV.
mysql2 gem with pg in Gemfile.config/database.yml for PostgreSQL. I used [Rails' template][2] as a starting point.