postgis字符串类型的时间转long类型的时间戳

SELECT EXTRACT(epoch FROM CAST(‘2017-12-06 00:17:10’ AS TIMESTAMP))-28800;

long转string格式的时间戳并且截取小时分钟：

select substring(to_char(to_timestamp("timestamp" / 1000),'YYYY-MM-DD HH24:MI:SS') from 12 for 5),* from data_trajectory