IBM DB2计算两个时间戳记间的时间差

DB2本身的内置函数，缺点是是近似值，用法如下：

SELECT

timestampdiff (256, char(timestamp('2017-05-27 23:00:00') - timestamp('2017-05-25 10:40:00'))) AS "间隔年",

timestampdiff (128, char(timestamp('') - timestamp(''))) AS "间隔季度",

timestampdiff (64, char(timestamp('') - timestamp(''))) AS "间隔月",

timestampdiff (32, char(timestamp('') - timestamp(''))) AS "间隔周",

timestampdiff (16, char(timestamp('') - timestamp(''))) AS "间隔日",

timestampdiff (8, char(timestamp('') - timestamp(''))) AS "间隔时",

timestampdiff (4, char(timestamp('') - timestamp(''))) AS "间隔分",

timestampdiff (2, char(timestamp('') - timestamp(''))) AS "间隔秒"

FROM SYSIBM.SYSDUMMY1;

相见时难别亦难