SELECT
"Orders"."order_id",string_agg(pr.product_name:: character
 varying, ',) as Product_names
 ,Count(Distinct "Orders"."order_id") as ordercount
FROM
"data"."orders" AS "Orders"
LEFT JOIN  data.items i On i."order_id"="Orders"."order_id"
LEFT join  data.products pr on pr."product_id"=i."product_id"
 WHERE TO_CHAR("Orders"."created_at_order",'YYYY-MM-DD')
BETWEEN '2019-02-01' AND '2019-04-30'
ORDER BY  "Orders"."order_id"