Querying jsonb field with #> through Postgrex adapter - postgresql

Question

I'm trying to query jsonb field via Postgrex adapter, however I receive errors I cannot understand.
Notification schema
def all_for(user_id, external_id) do
from(n in __MODULE__,
where: n.to == ^user_id and fragment("? #> '{\"external_id\": ?}'", n.data, ^external_id)
)
|> order_by(desc: :id)
end
it generates the following sql
SELECT n0."id", n0."data", n0."to", n0."inserted_at", n0."updated_at" FROM "notifications"
AS n0 WHERE ((n0."to" = $1) AND n0."data" #> '{"external_id": $2}') ORDER BY n0."id" DESC
and then I receive the following error
↳ :erl_eval.do_apply/6, at: erl_eval.erl:680
** (Postgrex.Error) ERROR 22P02 (invalid_text_representation) invalid input syntax for type json. If you are trying to query a JSON field, the parameter may need to be interpolated. Instead of
p.json["field"] != "value"
do
p.json["field"] != ^"value"
query: SELECT n0."id", n0."data", n0."to", n0."inserted_at", n0."updated_at" FROM "notifications" AS n0 WHERE ((n0."to" = $1) AND n0."data" #> '{"external_id": $2}') ORDER BY n0."id" DESC
Token "$" is invalid.
(ecto_sql 3.9.1) lib/ecto/adapters/sql.ex:913: Ecto.Adapters.SQL.raise_sql_call_error/1
(ecto_sql 3.9.1) lib/ecto/adapters/sql.ex:828: Ecto.Adapters.SQL.execute/6
(ecto 3.9.2) lib/ecto/repo/queryable.ex:229: Ecto.Repo.Queryable.execute/4
(ecto 3.9.2) lib/ecto/repo/queryable.ex:19: Ecto.Repo.Queryable.all/3
however if I just copypaste generated sql to psql console and run it, it will succeed.
SELECT n0."id", n0."data", n0."to", n0."inserted_at", n0."updated_at" FROM "notifications" AS n0 WHERE ((n0."to" = 233) AND n0."data" #> '{"external_id": 11}') ORDER BY n0."id" DESC
notifications-# ;
id | data | to | inserted_at | updated_at
----+---------------------+-----+---------------------+---------------------
90 | {"external_id": 11} | 233 | 2022-12-15 14:07:44 | 2022-12-15 14:07:44
(1 row)
data is jsonb column
Column | Type | Collation | Nullable | Default
-------------+--------------------------------+-----------+----------+-------------------------------------------
data | jsonb | | | '{}'::jsonb
What am I missing in my elixir notification query code?

Answer 1

Searching for solution I came across only using raw sql statement, as I couldn't figure out what's wrong with my query when it gets passed through Postgrex
so as a solution I found the following:
def all_for(user_id, external_ids) do
{:ok, result} =
Ecto.Adapters.SQL.query(
Notifications.Repo,
search_by_external_id_query(user_id, external_ids)
)
Enum.map(result.rows, &Map.new(Enum.zip(result.columns, &1)))
end
defp search_by_external_id_query(user_id, external_id) do
"""
SELECT * FROM "notifications" AS n0 WHERE ((n0."to" = #{user_id})
AND n0.data #> '{\"external_id\": #{external_id}}')
ORDER BY n0."id" DESC
"""
end
But as a result I'm receiving Array with Maps inside not with Ecto.Schema as if I've been using Ecto.Query through Postgrex, so be aware.