Google cloud platform 如何从按日期和限制1排序的BigQuery SQL中的联接中提取最早的子记录

我正在使用GCP中的BiqQuery分析Shopify模式数据，并尝试将Shopify客户数据加入到子记录（即订单数据）中，以便我可以找到在特定时间创建的每个客户的第一个订单，但将其限制为1…就像asc创建的订单一样，限制为1。我真的没办法弄明白

Select

customers.created_at as customer,
customers.orders_count,
orders.created_at,
orders.order_number

FROM `shopxxx.shopify.customers` as customers

Join  `shopxxx.shopify.orders` as orders

on customer = orders.customer

WHERE
 customers.orders_count  != 0 
AND customers.created_at > "2018-09-12 00:00:00 UTC" and  customers.created_at < "2019-09-12 23:59:59 UTC"

and  orders.source_name != 'web' 


order by  customers.created_at desc

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下面是BigQuery标准SQL

#standardSQL
SELECT
  customers.customer_id,
  customers.created_at AS customer,
  customers.orders_count,
  ARRAY_AGG(STRUCT(orders.created_at AS created_at, orders.order_number AS order_number) ORDER BY orders.created_at LIMIT 1)[OFFSET(0)].*
FROM `shopxxx.shopify.customers` AS customers
JOIN `shopxxx.shopify.orders` AS orders
ON customers.customer_id = orders.customer_id
WHERE customers.orders_count  != 0 
AND customers.created_at > "2018-09-12 00:00:00 UTC" AND  customers.created_at < "2019-09-12 23:59:59 UTC"
AND  orders.source_name != 'web' 
GROUP BY 1, 2, 3
ORDER BY customers.created_at DESC  

还是不同的方法

#standardSQL
SELECT
  customers.customer_id,
  customers.created_at AS customer,
  customers.orders_count,
  orders.created_at AS created_at, 
  orders.order_number AS order_number
FROM `shopxxx.shopify.customers` AS customers
JOIN (
  SELECT customer_id, ARRAY_AGG(STRUCT(created_at, order_number) ORDER BY created_at LIMIT 1)[OFFSET(0)].*
  FROM `shopxxx.shopify.orders` 
  WHERE source_name != 'web' GROUP BY customer_id
) AS orders
ON customers.customer_id = orders.customer_id
WHERE customers.orders_count  != 0 
AND customers.created_at > "2018-09-12 00:00:00 UTC" AND  customers.created_at < "2019-09-12 23:59:59 UTC"
ORDER BY customers.created_at DESC

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哇！这为我指明了学习的方向。我知道我今晚要做什么。