如何从postgreSQL中的时间戳中减去/添加分钟

Question

我有以下场景：

我有员工在工作中登记入住/退房。 但他们有10分钟的容忍度。

我从这个观点得到的后期条目：

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是签入时间， contacts.entry_time是雇员的计划输入时间。

这是condition contacts.entry_time vs precence_records.created来获取延迟的条目：

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

所以我想做那样的事情：

 (  ("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 TIMESTAMP contacts.entry_time VARCHAR

你能帮我吗

Answer 1

PostgreSQL中的日期，时间和时间戳可以添加/减去INTERVAL值：

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

如果您的timestamp字段是varchar，则可以先将其强制转换为时间戳数据类型，然后减去间隔：

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