amazon-redshift - redshift datediff 在使用 current_timestamp 时不起作用，但在使用 getdate() 函数时起作用

Question

我正在查询带有 datediff 的时间戳列 current_timestamp .但它给出了错误。

DATEDIFF(minute, timestamp_field ,current_timestamp::TIMESTAMP) 
or 
DATEDIFF(minute, timestamp_field ,current_timestamp)
DataType of timestamp_field is "TIMESTAMP DEFAULT '2016-03-29 20:33:33.404256'::timestamp without time zone"

输出:

ERROR: Specified types or functions (one per INFO message) not supported on Redshift tables.

Warnings: Function ""timestamp"(timestamp with time zone)" not supported. Function "timestamptz(timestamp with time zone,integer)" not supported. Function "timestamptz(text)" not supported.

但是如果我使用 ，下面的查询是有效的getdate() 功能

DATEDIFF(minute, timestamp_field ,getdate()::TIMESTAMP)

Answer 1

我只是简单地将带时区的时间戳转换为时间戳并且它正在工作。

例子:

select datediff(min, CURRENT_TIMESTAMP::timestamp, CURRENT_TIMESTAMP::timestamp);