sql - このコードを codeigniter で変換するには助けが必要です

Question

誰でもこれを変換するのを手伝ってもらえますか?

SELECT  id,ospos_people.first_name,ospos_people.last_name,customer_id,is_draft 
from
(SELECT  
          ospos_quotations.id,
          ospos_quotations.customer_id, 
          ospos_quotations.is_draft,
          ospos_quotations.date 
 from     ospos_quotations, ospos_quotation_items
 where  ospos_quotations.id= ospos_quotation_items.quotation_id 
 and ospos_quotation_items.line=1) AS T 
LEFT OUTER JOIN ospos_people on T.customer_id = ospos_people.person_id