Question

I’ve been searching all over for tips on this and have not really had any luck so far. With the mysql2 gem, trying to execute a stored procedure that returns multiple result sets gives me an unable to return results in this context error. I found someone had suggested to use the mysql gem instead (which I can’t find an explanation of what’s different between the two and what I might encounter by switching), and with that I’ve had more progress.

Here’s what I have so far:

>> db = ActiveRecord::Base.connection.raw_connection
=> #<Mysql:0x1056ae3d8>
>> ActiveRecord::Base.connection.select_all("CALL p_rpt_test('', '');")
=> [{"Header"=>"Client,Project,Type,Due Date,Assigned To"}]
>> db.more_results?
=> true
>> db.next_result
Mysql::Error: Commands out of sync; you can't run this command now
        from (irb):3:in `next_result'
        from (irb):3

Does anyone know of a way to get this to work, with mysql2 or mysql gems? The app is running rails 3.0.1.

Answer 1

Ok well I have no figured out how to get AR to do this so I’ve ended up just going low level and using the mysql driver itself, which mostly works…

data = Array.new
db = ActiveRecord::Base.connection.raw_connection
header = db.query("CALL #{self.proc}(#{args});")
header.each {|r| data << r}
if db.next_result
  rows = db.store_result
  rows.each {|r| data << r}
end

ActiveRecord::Base.connection.reconnect!

It works, but I can’t imagine there’s not a better way. Also I have to reconnect after this or I get an error on the next query, and I haven’t found a way to properly close the session. Oh and I have to use the mysql gem and not mysql2.

Grrrrr.