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[英]Casbah (Scala) Generating a query statement with nested conditions ($OR $AND)
[英]Query Deep Nested MongoDB Object with Casbah [Scala]
{'_id': ObjectId('589df735be9fa2077dc5bb2e'),
'name': 'train.2',
'samples': [{'processed': {'eulerAngles': [1.946705159018607,
-0.01405100477972897,
0.02015610032297892]},
'raw': {'accel': [0.01548936311155558,
0.0002011665492318571,
0.02126962691545486],
'gyro': [0.06626824289560318,
0.1328225582838058,
0.001385239884257317]},
'timestamp': '2017-02-10T17:24:04.283Z'},
{'processed': {'eulerAngles': [1.948553665755181,
-0.01403613777322358,
0.01932380767991558]},
'raw': {'accel': [0.01380419824272394,
-0.001462434651330113,
0.01273023523390293],
'gyro': [0.09209229052066803,
0.07342914491891861,
0.01548820454627275]},
'timestamp': '2017-02-10T17:24:04.293Z'}}]}
對於樣本數組中的每個樣本,我需要提取數組加速度。 我寫了下面的代碼
val el = db("samples").findOne(MongoDBObject("name" -> name))
var t_series_seq: Array[Array[Double]] = Array()
for (m <- el.get("samples")) t_series_seq :+ m("raw")("accel")
這是返回value foreach is not a member of AnyRef
。 我需要告訴el.get(“ samples”)類型,但是我不知道如何分辨它是一個復雜的Map對象。
好吧,所以Casbah文檔真的很糟糕。 實際上,我是通過閱讀專門針對數據科學的Scala中有關將MongoDB與Scala結合使用的一章而了解到這一點的。
我的代碼如下:
val dbSamples = db("samples").find(MongoDBObject("name" -> name))
var timesSeries: Array[TimeSeries] = Array()
for (s <- dbSamples) {
var tSeries_seq: Array[Array[Double]] = Array()
val measures = s.getAs[List[DBObject]]("samples").get
for (m <- measures) {
println(m.getAs[DBObject]("raw").get.getAs[List[Double]]("accel").get.toArray)
tSeries_seq = tSeries_seq :+ m.getAs[DBObject]("raw").get.getAs[List[Double]]("accel").get.toArray
}
timesSeries = timesSeries :+ new TimeSeries(tSeries_seq, s.getAs[Integer]("valid").get)
}
timesSeries
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