mysql - 只显示 mysql 子查询返回 null 的行

Question

我正在尝试查询收据表，从数据库中提取第一笔交易在特定时间范围内的订单号。这是我目前所拥有的:

SELECT id, order_number, 
(
  SELECT id FROM receipts 
  WHERE received < r.received AND order_number = r.order_number 
  LIMIT 1
) priorPayment 
FROM receipts r 
WHERE received > 1416384000 AND received < 1416470399 
ORDER BY id DESC

这工作正常，除了我想过滤掉任何返回 priorPayment 的东西(所以只显示这个子查询返回 null 的地方)现在它返回所有东西。有什么建议吗？

Answer 1

尽管您可以为此子查询或 having 子句使用子查询，但我建议您只使用 left join

SELECT r.id, r.order_number
FROM receipts r LEFT JOIN
     receipts r2
     ON r2.received < r.received and r2.order_number = r.order_number
WHERE r.received > 1416384000 AND r.received < 1416470399 AND
      r2.order_number is NULL
ORDER BY r.id DESC;