如何在postgreSQL中从时间戳中减去/添加分钟

Question

我有以下场景：

我有员工注册他们的签到/离开他们的工作。但他们有10分钟的耐受性。

我在此视图中获得的最新条目如下：

CREATE OR REPLACE VIEW employees_late_entries
(
  id,
  created_datetime,
  entry_datetime,
  contact_id,
  contact_name,
  user_id,
  employees_perm_id
)
AS 
 SELECT precence_records.id,
    precence_records.created AS created_datetime,
    ("substring"(precence_records.created::text, 0, 11) || ' '::text) || contacts.entry_time::text AS entry_datetime,
    contacts.id AS contact_id,
    contacts.name AS contact_name,
    precence_records.user_id,
    precence_records.employees_perm_id
   FROM precence_records,
    contacts
  WHERE 
    precence_records.type::text = 'entry'::text AND 
    contacts.employee = true AND 
    contacts.id = precence_records.contact_id AND 
    ( ("substring"(precence_records.created::text, 0, 11) || ' '::text) || contacts.entry_time::text) < precence_records.created::text AND 
    precence_records.employees_perm_id IS NULL;

precence_records.created是员工的签到时间，contacts.entry_time是员工的计划条目时间。

这是获取最新条目的condition contacts.entry_time与precence_records.created：

 ( ("substring"(precence_records.created::text, 0, 11) || ' '::text) || contacts.entry_time::text) < precence_records.created::text

所以我想做这样的事情：

 (  ("substring"(precence_records.created::text, 0, 11) || ' '::text) || (contacts.entry_time::text + 10 MINUTES)  ) < precence_records.created::text

数据类型：

precence_records.created时间戳contacts.entry_time VARCHAR

你能帮帮我吗？

Answer 1

PostgreSQL中的日期、时间和时间戳可以与间隔值相加/相减：

SELECT now()::time - INTERVAL '10 min'

如果您的时间戳字段是varchar，您可以先将其转换为timestamp数据类型，然后再减去间隔：

 ( (left(precence_records.created::text, 11) || ' ') ||
   (contacts.entry_time::time + INTERVAL '10min')::text )::timestamp <
 precence_records.created::timestamp