我正在尝试从具有时区数据类型列的时间戳中提取本地时间戳。
我目前有下表架构:
ARRIVAL_DTM TIMESTAMP(0) WITH TIME ZONE
我能够将时间戳转换为日期格式,而无需 teradata 对其强制时区,如下所示:
SEL
CAST(ARRIVAL_DTM AS DATE AT SOURCE TIME ZONE) AS Date,
ARRIVAL_DTM AS 'Timestamp with Time Zone'
From tblname;
结果:
Date Timestamp with Time Zone
2021-06-01 2021-06-01 23:13:51-06:00
2021-06-01 2021-06-01 23:27:58-06:00
2021-06-02 2021-06-02 01:28:50-06:00
2021-06-02 2021-06-02 02:41:29-06:00
从上面的第一条记录来看,如果应用了时区,日期应该是2021-06-02
我想要做的是提取时间戳而不 td 自动将时区添加到结果中。
我希望得到如下结果,没有时区的列时间戳:
Timestamp without Time Zone Timestamp with Time Zone
2021-06-01 23:13:51 2021-06-01 23:13:51-06:00
2021-06-01 23:27:58 2021-06-01 23:27:58-06:00
2021-06-02 01:28:50 2021-06-02 01:28:50-06:00
2021-06-02 02:41:29 2021-06-02 02:41:29-06:00
如果我确实转换为timestamp(0)
,则最终结果是时间戳,包括我不想要的时区。td 会自动给我时间戳+时区。
SEL
CAST(ARRIVAL_DTM AS TIMESTAMP(0)) AS Date,
ARRIVAL_DTM AS 'Timestamp with Time Zone'
From tblname;
结果:
Date Timestamp with Time Zone
2019-04-04 19:28:38 2019-04-04 13:28:38-06:00
2019-05-02 19:30:41 2019-05-02 13:30:41-06:00
2019-05-30 16:36:13 2019-05-30 10:36:13-06:00
编辑:
只有当我将其转换为VARCHAR
然后使用INSTR
等删除正确的 6 个字符时,我才能从时间戳列中提取时区值。这需要大量的字符串操作
TD中的内置功能/选项没有另一种方法吗?
SELECT
LEFT(
CAST( ARRIVAL_DTM AS VARCHAR(40) ),
CAST(
INSTR( CAST( ARRIVAL_DTM AS VARCHAR(40) ),
RIGHT( CAST ( ARRIVAL_DTM AS VARCHAR(40) ), 6 )
)
AS INTEGER ) - 1 AS 'Timestamp without Time Zone (VARCHAR)'
),
ARRIVAL_DTM AS 'Timestamp with Time Zone (TIMESTAMP)'
From tblname;
结果:
Timestamp without Time Zone (VARCHAR) Timestamp with Time Zone (TIMESTAMP)
2019-06-29 23:22:51 2019-06-29 23:22:51-06:00
2019-07-16 05:59:46 2019-07-16 05:59:46-06:00
2019-07-20 18:44:18 2019-07-20 18:44:18-06:00