postgresql - 将表示时间戳的字符串转换为 PostgreSQL 中的实际时间戳？

Question

在 PostgreSQL 中:我使用 to_timestamp() 将 string 转换为 timestamp:

select * from ms_secondaryhealthcarearea
where to_timestamp((COALESCE(update_datetime, '19900101010101'),'YYYYMMDDHH24MISS') 
    > to_timestamp('20121128191843','YYYYMMDDHH24MISS')

但是我得到这个错误:

ERROR:  syntax error at end of input
LINE 1: ...H24MISS') >to_timestamp('20121128191843','YYYYMMDDHH24MISS')
                                                                       ^
********** Error **********

ERROR: syntax error at end of input
SQL state: 42601
Character: 176

为什么？如何将字符串转换为时间戳？

Answer 1

左括号太多。试试这个:

select * 
from ms_secondaryhealthcarearea 
where to_timestamp(COALESCE(update_datetime, '19900101010101'),'YYYYMMDDHH24MISS') >to_timestamp('20121128191843','YYYYMMDDHH24MISS')

您在 to_timestamp 处有两个左括号:

where to_timestamp((COA.. -- <-- the second one  is not needed!