我想从一些日期时间增量中得到毫秒精度。我在hive中没有看到毫秒（）函数。
考虑一下：

with t as (
    select (CAST(1481652239798 AS TIMESTAMP) - CAST(1481652228576 as timestamp)) 
    as delta
) 
select delta from t;

0 00:00:11.222000000

如果我能将输出转换成字符串并提取句点后面的部分，我就可以处理这个问题。

with t as (
    select (CAST(1481652239798 AS TIMESTAMP) - CAST(1481652228576 as timestamp)) 
    as delta
) 
select instr(delta, '.') from t

11 -- correct index of '.'

因此instr（）将delta视为一个字符串，但我不能将其子字符串：

with t as (
    select (CAST(1481652239798 AS TIMESTAMP) - CAST(1481652228576 as timestamp)) 
    as delta
) 
select substr(delta, 11) from t; -- directly supplying instr() leads to a different bug with parsing the query syntax

No matching method for class org.apache.hadoop.hive.ql.udf.UDFSubstr with (interval_day_time, int)

有解决办法吗？