arrays - Arrayformula 在 Google 表格中查找条件的下一个值

Question

我的工作表中有“表单回复”选项卡，我可以在其中整理包含起始日期时间戳、编号和名称的信息。我想创建一个数组公式，它将用日期时间戳填充最后一列，作为数据集中下一个名称条目。我想避免提交完成日期时间戳的需要。

我已经尝试过

=ARRAYFORMULA(if(A:A="","",vlookup(C:C,{C2:C20,A2:A20},2,false))) 

希望 arrayformula 会在填充更多行时更改搜索范围，但事实并非如此。

它必须是位于第一行的数组公式，不能使用单个公式并复制并粘贴它，因为它的表单响应会为每个答案添加行

        Now


+---------------------+--------------+--------+
|      Timestamp      | Group number | Picker |
+---------------------+--------------+--------+
| 29/01/2020 21:31:45 |         3001 | Ben    |
| 30/01/2020 19:42:20 |         3002 | Ben    |
| 30/01/2020 20:04:51 |         3006 | Jon    |
| 30/01/2020 20:05:08 |         3018 | Jon    |
| 30/01/2020 22:31:45 |         3019 | Ben    |
| 31/01/2020 23:31:45 |         3020 | Jon    |
| 01/02/2020 21:31:45 |         3021 | Ben    |
+---------------------+--------------+--------+





    Expected



+---------------------+--------------+--------+---------------------+
|      Timestamp      | Group number | Picker |    ARRAYFORMULA     |
+---------------------+--------------+--------+---------------------+
| 29/01/2020 21:31:45 |         3001 | Ben    | 30/01/2020 19:42:20 |
| 30/01/2020 19:42:20 |         3002 | Ben    | 30/01/2020 22:31:45 |
| 30/01/2020 20:04:51 |         3006 | Jon    | 30/01/2020 20:05:08 |
| 30/01/2020 20:05:08 |         3018 | Jon    | 31/01/2020 23:31:45 |
| 30/01/2020 22:31:45 |         3019 | Ben    | 01/02/2020 21:31:45 |
| 31/01/2020 23:31:45 |         3020 | Jon    |                     |
| 01/02/2020 21:31:45 |         3021 | Ben    |                     |
+---------------------+--------------+--------+---------------------+

Answer 1

尝试:

={""; ARRAYFORMULA(IFNA(VLOOKUP(C2:C, SORT({C2:C, A2:A}, 2, 0), 2, 0)))}

---

更新:

={"ARRAYFORMULA"; ARRAYFORMULA(IFNA(VLOOKUP(
         C2:C&COUNTIFS(C2:C, C2:C, ROW(C2:C), "<="&ROW(C2:C))+1, 
 FILTER({C2:C&COUNTIFS(C2:C, C2:C, ROW(C2:C), "<="&ROW(C2:C)), A2:A}, 
 ROW(C2:C)-MATCH(C2:C, C2:C, 0)<>1), 2, 0)))}