PG数据库，时间戳转换

PG数据库，时间戳转换

将毫秒/秒转成格式化后的时间
select to_char(to_timestamp(time),'yyyy-MM-dd HH24-MI-SS') as time  from tablename;

#统计每个月的记录数
select to_char(to_timestamp(time),'yyyy-MM') as time ,count(1) from tablename group by time;