euphbriggs
Ecto embedded schema migration
I have a schema that contains an embedded schema, which I would like to rename a field on. For example:
schema "menu_items" do
field(:plu, :string)
# ...
embeds_many :build_items, BuildItem, on_replace: :delete do
field(:item_id, :string)
# ...
end
end
I want to rename the build_items item_id field to value. Is there a way to do this with an Ecto migration or will I need to create the new field, copy the data over, then delete the old field?
Any pointers are very much appreciated.
Thanks,
Ben
Most Liked
euphbriggs
I posted this question on StackOverflow and here’s the solution that I ended up with. Thanks for pointing me in the right direction. I think I probably would have wasted another day’s worth of time before I even considered writing the SQL directly. Ecto’s really spoiled me. I used to write all my SQL queries/commands and now I rarely need to!
UPDATE menu_items
SET build_items = t.newValue
FROM (WITH temp AS (SELECT id, UNNEST(build_items) b FROM menu_items)
SELECT
id,
array_agg(b - 'item_id' || jsonb_build_object('value', coalesce(b -> 'item_id', b -> 'value'))) AS newValue
FROM temp
GROUP BY id) AS t
WHERE menu_items.id = t.id;
Last Post!
zaljir
Old topic, but still useful. The custom query can be simplified a little:
UPDATE menu_items t1 SET build_items = (
SELECT json_agg(el::jsonb - 'item_id' || jsonb_build_object('value', el -> 'item_id'))
FROM menu_items t2, jsonb_array_elements(t2.build_items) AS el
WHERE t1.id = t2.id
);
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Move fast and fix things! Error tracking with less noise for Elixir devs who love to ship. Start your free dev account.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #websockets
- #supervisor
- #elixirconf-us
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #security
- #hex
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking for Elixir devs who love to ship. Start your free account.
Practical resources that improve the lives of professional developers.
Develop your skills with books, videos, and courses.
Producing high quality Elixir screencasts since 2017.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"