無拼接時：
SELECT scan_time + '5 day' FROM tbl_temp_record
SELECT scan_time + '-5 day' FROM tbl_temp_record
拼接字段時：
SELECT scan_time + 5 || ' day' FROM tbl_temp_record 報錯
ERROR: operator does not exist: timestamp without time zone + integer
SQL 狀態: 42883
SELECT scan_time + '5' || ' day' FROM tbl_temp_record 不是想要的結果
正確寫法：
SELECT scan_time + (5 || ' day')::interval FROM tbl_temp_record
SELECT scan_time + ('-' || 5 || ' day')::interval FROM tbl_temp_record
或
SELECT scan_time + 5*interval '1 day' FROM tbl_temp_record
SELECT scan_time + 5*interval '-1 day' FROM tbl_temp_record
---------------------
作者：宮辰雅軒
來源：CSDN
原文：https://blog.csdn.net/r_rcgz/article/details/53171256
版權聲明：本文為博主原創文章，轉載請附上博文鏈接！