html - 如何从 mongoDB 流星 js 中获取 Objectid？

Question

我正在使用流星和 mongoDB 我有这个 mongoDB 对象：

{ 
"_id" : ObjectId("57987ee00b04a118688b6fe7"), 
"startDate" : ISODate("2016-07-27T09:29:04.341+0000"), 
"processType" : "import", 
"marque" : "VPPPP", 
"inputFile" : "C:\\Orchestra.Data\\CP\\xml\\Booking_PVCP_3753510_20150623_111115.xml", 
"processQueue" : true, 
"status" : "finished", 
"result" : "success", 
"tasks" : [
    {
        "name" : "import_validation", 
        "startDate" : ISODate("2016-07-27T09:29:04.881+0000"), 
        "endDate" : ISODate("2016-07-27T09:29:04.892+0000"), 
        "message" : "this is a message", 
        "status" : "finished", 
        "resulta" : "error"
    }, 
    {
        "name" : "import_GetStockValues", 
        "startDate" : ISODate("2016-07-27T09:29:04.889+0000"), 
        "endDate" : ISODate("2016-07-27T09:29:04.892+0000"), 
        "message" : "this is a message", 
        "status" : "finished", 
        "resulta" : "success"
    }, 
    {
        "name" : "import_WriteInExcel", 
        "startDate" : ISODate("2016-07-27T09:29:04.889+0000"), 
        "endDate" : ISODate("2016-07-27T09:29:04.893+0000"), 
        "message" : "this is a message", 
        "status" : "finished", 
        "resulta" : "success"
    }, 

]
}

我想得到_id这个对象的。我怎样才能做到这一点？