Why does Rails 3 with Mysql2 Gem ActiveRecord::Base.connection.execute(sql) return Array not Hash?

Question

I\'m in the process of upgrading an application to Rails 3. I\'ve decided to go with the mysql2 gem. There\'s some legacy code in the app that makes calls like:

Answer 1

instead of

result = ActiveRecord::Base.connection.execute(sql)

do

results = ActiveRecord::Base.connection.exec_query(sql)

And that'll do exactly what you want. In particular,

results.first

will be a hash, and so on.

Thanks to @_fx for figuring this out!

For more, see http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/Mysql2Adapter.html#method-i-exec_query

Answer 2

Improving dan's answer, Rails 3.2.8 won't accept RAILS_ENV.

    config = ActiveRecord::Base.configurations[Rails.env].symbolize_keys
    conn = Mysql2::Client.new(config)
    conn.query("select * from users").each do |user|
        # user should be a hash
    end

Answer 3

If you just want to reuse the database.yml configuration, you can do this:

config = ActiveRecord::Base.configurations[RAILS_ENV].symbolize_keys
conn = Mysql2::Client.new(config)
conn.query("select * from users").each do |user|
  # user should be a hash
end

Answer 4

results = ActiveRecord::Base.connection.select(sql) 

table header

results.first.keys.each do |key|
 key
end

table data

results.each do |result| %>
  result.values.each do |value| %>
    value
  end
end

Answer 5

I faced a similar issue a while back and found this to work:

result = ActiveRecord::Base.connection.execute(sql) 
result.each(:as => :hash) do |row| 
   row["field"] 
end

edit: you could also use the select_all method of the connection object that returns a hash