CODEWITHSUNDEEP
sqlruby-on-railspostgresqlrails-activerecord
Tasawar Hussain
Tasawar Hussain

Reputation: 765

Get random records from rails 5 but keep one record(based on some value ) on top

I have a Question table. It has a dummy question in it , i want to get the question in random but that dummmy question should always be on top in the returned ActiveRecord collection. I can get the records in random buy using Random() function which is working fine but that dummy question has also random position which i dont want, i want it to be on first position. Any solution would be helpful.

Question table columns: id, statement, answer The dummy question has blank statement.

Query i am using 

Question.all.order("Random()")

I am using PostgreSQL.

Upvotes: 0

Views: 292

Answers (1)

Pavel Mikhailyuk
Pavel Mikhailyuk

Reputation: 2877

First option:

select_clause = "(CASE WHEN (statement = '') THEN 0 ELSE Random() END) as dummy, questions.*"
Question
  .select(select_clause)
  .order('dummy')

Second option:

select_clause = "(statement <> '') as dummy, questions.*"
Question
  .select(select_clause)
  .order('dummy, Random()')

Edit: statement shouldn't contain NULL in both options

Upvotes: 2

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