Dynamic query builder stack too deep for Arel query Rails

Question

I am looking for a way to construct a big dynamic query in Rails and applying an update to the given ActiveRecord relationship:

For example:

my_big_set = Set.new(big_array)
to_update_relationship = my_big_set.reduce(none) do |query, values_to_check|
                            where('condition = ? and condition_two = ?', values_to_check[:first], values_to_check[:two]).or(query)
                         end
    
to_update_relationship.update_all(field_to_update: true)

It works well when to_update_relationship is not too big. But if it gets bigger then the reduce output triggers a SystemStackError: stack level too deep error when it constructs the Arel query.

Is there a clever way to workaround it? (other than splitting the input or increasing the ruby system stack size).

Thanks

PS: using rails 6 and ruby 2.7

Answer 1

my solution finally is:

my_big_set = Set.new(big_array)
subquery = '(condition = ? and condition_two = ?)'
query = Array.new(my_big_set, subquery).join(' OR ')
query_values = my_big_set.map do |values_to_check|
   [values_to_check[:first], values_to_check[:two]]
end.flatten

where(query, *query_values).update_all(field_to_update: true)

that way, we construct:

1. the SQL query
2. the values to pass to where()
3. we still use active record where() in order to be protected from injection etc...

And this fixes the limit!