如何将mongodb中的记录与聚合合并

Question

我有一个名为“timestamp”的集合，每个time_in，time_out，break_start和break_end都有单独的记录。

我想要的是合并同一日期的记录。 由此： 未合并数据：

{ 
    "_id" : ObjectId("5a94f3e461613268eaecc59c"), 
    "staff_id" : NumberInt(173), 
    "time_in" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "time_out" : null, 
    "break_start" : null, 
    "break_end" : null, 
    "break_type" : null, 
    "train_delay" : true, 
    "createdAt" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "updatedAt" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "__v" : NumberInt(0)
}
{ 
    "_id" : ObjectId("5a94f411e5e2d568f1dae527"), 
    "staff_id" : NumberInt(173), 
    "time_in" : null, 
    "time_out" : null, 
    "break_start" : ISODate("2018-02-27T04:00:00.000+0000"), 
    "break_end" : null, 
    "break_type" : "60m", 
    "train_delay" : false, 
    "createdAt" : ISODate("2018-02-27T04:00:00.000+0000"), 
    "updatedAt" : ISODate("2018-02-27T04:00:00.000+0000"), 
    "__v" : NumberInt(0)
}
{ 
    "_id" : ObjectId("5a94f41ae5e2d568f1dae528"), 
    "staff_id" : NumberInt(173), 
    "time_in" : null, 
    "time_out" : null, 
    "break_start" : null, 
    "break_end" : ISODate("2018-02-27T04:59:00.000+0000"), 
    "break_type" : null, 
    "train_delay" : false, 
    "createdAt" : ISODate("2018-02-27T04:59:00.000+0000"), 
    "updatedAt" : ISODate("2018-02-27T04:59:00.000+0000"), 
    "__v" : NumberInt(0)
}
{ 
    "_id" : ObjectId("5a94f421e5e2d568f1dae529"), 
    "staff_id" : NumberInt(173), 
    "time_in" : null, 
    "time_out" : ISODate("2018-02-27T10:05:00.000+0000"), 
    "break_start" : null, 
    "break_end" : null, 
    "break_type" : null, 
    "train_delay" : false, 
    "createdAt" : ISODate("2018-02-27T10:05:00.000+0000"), 
    "updatedAt" : ISODate("2018-02-27T10:05:00.000+0000"), 
    "__v" : NumberInt(0)
}

这是以下形象： Not yet merge records.

进入： 合并数据：

{ 
    "_id" : ObjectId("5a94f3e461613268eaecc59c"), 
    "staff_id" : NumberInt(173), 
    "time_in" : { 
    "_id" : ObjectId("5a94f3e461613268eaecc59c"), 
    "staff_id" : NumberInt(173), 
    "time_in" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "time_out" : ISODate("2018-02-27T10:05:00.000+0000"), 
    "break_start" : ISODate("2018-02-27T04:00:00.000+0000"), 
    "break_end" : ISODate("2018-02-27T04:59:00.000+0000"),  
    "break_type" : null, 
    "train_delay" : true, 
    "createdAt" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "updatedAt" : ISODate("2018-02-27T00:40:00.000+0000"), 
    "__v" : NumberInt(0)
}

这是以下形象： Merged records