Event::where('created_at','>',Carbon::parse($request->start_date))
->where('created_at','',Carbon::parse($request->end_date))
//两个where限制开始结束时间
->groupBy('date')
->get([DB::raw('DATE(created_at) as date'),DB::raw('COUNT(*) as value')])
->toArray();

Event::where('created_at','>',Carbon::parse('2017-01-01'))
->where('created_at','',Carbon::parse('2017-11-09'))
->groupBy('day')
->get([
//通过date_format()来格式化created_at字段
 DB::raw('DATE_FORMAT(created_at,\'%H') as day'),
 DB::raw('COUNT(*) as value')])
->toArray()

$(function () {
/*设置开始结束时间*/
 var start = moment().subtract(30, 'days');
 var end = moment().subtract(-1,'day');
 var datas = {};
/*选择之后，将时间重新赋值input*/
 function cb(start, end) {
  $('#reportrange span').html(start.format('YYYY/MM/DD') + ' - ' + end.format('YYYY/MM/DD'));
 }
 $('#reportrange').daterangepicker({
 startDate: start,
 endDate: end,
 /*本地化数据*/
 locale: {
  "format": "YYYY/MM/DD",
  "separator": " - ",
  "applyLabel": "应用",
  "cancelLabel": "关闭",
  "fromLabel": "From",
  "toLabel": "至",
  "customRangeLabel": "自定义",
  "weekLabel": "W",
  "daysOfWeek": ["Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"
  ],
  "monthNames": ["一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月"
  ],
  "firstDay": 1
 },
 ranges: {
  '今天': [moment(), moment().subtract(-1, 'days')],
  '昨天': [moment().subtract(1, 'days'), moment()],
  '前7天': [moment().subtract(7, 'days'), moment()],
  '前30天': [moment().subtract(30, 'days'), moment()],
  '本月': [moment().startOf('month'), moment().endOf('month').subtract(-1,'day')],
  '上月': [moment().subtract(1, 'month').startOf('month'), moment().subtract(1, 'month').endOf('month').subtract(-1,'day')],
  '所有': [moment("2017-09-25"), moment().subtract(-1, 'days')]
 }
}, cb);

 cb(start, end);
});