sql - Teradata 连接多个字符串列格式作为时间戳

Question

我对 Teradata 还是很陌生，所以请原谅，但我有两列，一列是日期，一列是 4 位 varchar 作为时间(24 小时)

下面是我用来连接字段以使其可读的内容，但我想让结果作为有效的时间戳出现，以便我可以执行计算。

cast(SCHEDULE_DATE as date format 'yyyy-mm-dd') || ' ' || substr(START_TIME,0,3) || ':' || substr(START_TIME,2,2)

这是我从上述查询中获得的结果示例。2017-01-25 13:30

当我像这样运行查询时

cast(cast(SCHEDULE_DATE as date format 'yyyy-mm-dd') || ' ' || substr(START_TIME,0,3) || ':' || substr(START_TIME,2,2) as Timestamp ) as TESTVALUE

我得到无效的时间戳

Answer 1

select  '2017-02-15'    as schedule_date
       ,'2233'          as start_time
       ,to_timestamp (schedule_date || start_time,'yyyy-mm-ddhh24mi')    as ts
;

---

+---------------+------------+----------------------------+
| schedule_date | start_time | ts                         |
+---------------+------------+----------------------------+
| 2017-02-15    | 2233       | 2017-02-15 22:33:00.000000 |
+---------------+------------+----------------------------+

---

附言
substr 参数错误。
Teradata 使用 1 作为起点。

---

select  '1234'                  as start_time
       ,substr(start_time,0,3)  as original_1
       ,substr(start_time,2,2)  as original_2
       ,substr(start_time,1,2)  as correct_1
       ,substr(start_time,3,2)  as correct_2
;       

---

+------------+------------+------------+-----------+-----------+
| start_time | original_1 | original_2 | correct_1 | correct_2 |
+------------+------------+------------+-----------+-----------+
| 1234       | 12         | 23         | 12        | 34        |
+------------+------------+------------+-----------+-----------+