如何处理postgresql日期字段中的空值

Question

我必须忽略null日期列中的行。我该怎么做？

select s."SR Closed Date"::date,
       s."Service Request Number",
       a."Activity ID" 
from sr_data_master s,
     activity_master a
where s."Service Request Number" = a."Service Request Number"
and a."Service Request Number" is not null 
and a."Service Tag" is not null 
and a."Activity ID" is not null
and s."SR Closed Date"::date is not NULL
group by s."Service Request Number",
         s."SR Closed Date"::date,
         a."Activity ID";

我收到错误：

 invalid input syntax for type date: "NULL" 

Answer 1

null是日期的有效值。从错误消息来看，似乎您在该列中存储了字符串“null”。您可以明确地检查它：

LOWER(s."SR Closed Date") <> 'null'

date或者只是从条款中删除铸造group by。