til/rails/select-value-for-sql-counts.md

Select Value For SQL Counts

If you are like me and prefer writing raw SQL over the Arel DSL for counting stuff in your database, then the select_value method will come in handy. Write a command similar to the following with a type cast to get the count of whatever.

> sql = 'select count(*) from posts where published_at is not null'
=> "select count(*) from posts where published_at is not null"
> ActiveRecord::Base.connection.select_value(sql).to_i
   (0.6ms)  select count(*) from posts where published_at is not null
=> 42