Rails: Using distinct with where

Question

I have an ActiveRecord query:

Shareholder.where(is_company: false).distinct

which gives me the error:

ActiveRecord::StatementInvalid: PG::UndefinedFunction: ERROR: could not identify an equality operator for type json

The SQL query created by ActiveRecord:

SELECT DISTINCT "shareholders".*
FROM "shareholders"
WHERE "shareholders"."deleted" = $1 AND "shareholders"."is_company" = $2

I'm a bit puzzled that this does not work. What is wrong?

http://stackoverflow.com/questions/23509740/distinct-on-postgresql-json-data-column — Andrey Deineko, Sep 29 '16 at 10:21
looking at your ActiveRecord: query seems like your Shareholder model is having some issue — sat's, Sep 29 '16 at 10:31
after removing the json type column it does work. I'll look in to this — Matthias, Sep 29 '16 at 11:57

score 5 · Answer 1 · answered Sep 29 '16 at 12:40

5

Distinct does not work with json column, but you can try this

Shareholder.select("DISTINCT ON (shareholders.id) shareholders.*").where(is_company: false).distinct

answered Sep 29 '16 at 12:40

Elena Unanyan

1 Answers1