如何在原始查询（rails + postgres）中使用动态 id 数组？

Question

I have this code

Language.all.map{|l|[l.language, l.accounts.joins(:children).where("accounts.id IN (?)", @accounts.ids).uniq.count]}

I am trying to get this as output

[["eng", 5] ["span", 3] ["ital", 4] ... ]

I want to write it as a raw query.

I tried this,

ActiveRecord::Base.connection.execute("select languages.language, (SELECT COUNT(*) FROM accounts where accounts.language_id = languages.id) from languages").values

but i need to pass accounts.ids dynamic.. like this

select languages.language, (SELECT COUNT(*) FROM accounts where accounts.language_id = languages.id AND (accounts.id IN (#{@accounts.ids})) from languages"

when i tried to pass accounts.id IN #{@accounts.ids} i am getting error (accounts.id IN ([2839, 284.. .. this should have been IN (2839, 284..) instead, it is taking array.

How to pass it dynamically?

Answer 1

You can try:

"... accounts.id IN (#{@accounts.ids.join(',')})"

Hope it helps.

Answer 2

You can use where(id: @accounts.ids) or where("account.ids": @accounts.ids) or where("account.ids IN?, @accounts.ids) . I believe ActiveRecord should understand all of them.

• http://guides.rubyonrails.org/active_record_querying.html#array-conditions
• http://guides.rubyonrails.org/active_record_querying.html#subset-conditions

Answer 3

The above 2 answers won't work if you are attempting to use an array of strings in a raw sql query. For a raw sql statement, you can use ActiveRecord's sanitize_sql_array method.

languages = ['eng', 'span', 'chin', 'ital']
base_query = "SELECT * FROM languages WHERE id IN (?)"
sanitized_query = ActiveRecord::Base.send :sanitize_sql_array, [base_query, languages]
ActiveRecord::Base.connection.execute(sanitized_query)