Snowflake SQL 错误 - 函数“-”的参数类型无效：(TIMESTAMP_NTZ(9)、TIMESTAMP_NTZ(9))

Question

当我尝试减去时间戳并执行窗口函数（lead、lag和partition by）时，出现此错误：

函数“-”的参数类型无效：(TIMESTAMP_NTZ(9)、TIMESTAMP_NTZ(9))

尝试过date_diff，但这不能与窗口函数一起使用

SELECT 
   user_id,
   event,
   received_at,
   received_at - LAG( received_at,1) OVER (PARTITION BY user_id ORDER BY received_at) AS last_event
FROM 
   segment_javascript.help_center_opened

Answer 1

您不能通过仅减去两个日期来获得数字来通过“Oracle 方式”来完成此操作，您必须使用带有度量单位/比例的 diff 函数，例如：

SELECT 
   ts, 
   TIMESTAMPDIFF(MILLISECONDS, LAG(ts, 1) OVER (ORDER BY ts), ts) tsd
FROM 
   (VALUES (CURRENT_TIMESTAMP), (DATEADD(DAY, 1, CURRENT_TIMESTAMP))) v(ts);