sql - 根据 SQL 中耗时返回 true/false

Question

假设我们有一个如下所示的 SQL 查询

select now()-insert_time AS time_elapsed, *
from account
where enabled = true AND machine = 'one'
limit 1

是否可以为 now()-insert_time AS time_elapsed 返回一个 bool 列？如果超过 4 小时，我希望它为真，如果少于 4 小时，则为假。

Answer 1

您可以直接在查询中比较它

 select now()-insert_time AS time_elapsed,
        now()-insert_time >= '4 hours' as status,
        * 
   from account 
  where enabled = true 

一般情况下，放在CASE表达式中，其他值输出

 select now()-insert_time AS time_elapsed,
        CASE 
             WHEN now()-insert_time >= '4 hours' THEN 'Greater than 4 hours'
             ELSE 'Less than 4 hours'
        END as status,
        * 
   from account 
  where enabled = true 
        AND machine = 'one'  
  limit 1

希望对您有所帮助。