1.时间戳和时间对象可以灵活转变: let n = new Date() // 返回的是当前时间对应的国际时间 let nt =n.getTime() let n2 =new Date(nt) console.log(n,nt,n2) 输出为当前时间和时间戳: Date 2018-12-06T06:41:56.217Z 1544078516217 Date 2018-12-06T06:41:56.217Z 2.时间转换的字符串参数格式不同,返回的时间格式有时会不同 // 时分秒如果有参数,返回的
/* 时间转换start */ public static void main(String args[]) { Date nowTime = new Date(); System.out.println(nowTime); SimpleDateFormat time = new SimpleDateFormat("yyyy/M/d"); BeanDayTraffic bd = new BeanDayTraffic(); System.out.println(time.format(n
1.inner join ,left join 与 right join (from 百度知道) 例表aaid adate1 a12 a23 a3表bbid bdate1 b12 b24 b4 (1)两个表a,b相连接,要取出id相同的字段 select * from a inner join b on a.aid = b.bid 此时的取出的是:1 a1 b12 a2 b2 (2)left join 指:select * from a left jo