我一直在搜索，还没有找到一种解决方案，该解决方案是如何使用Spark
SQL查询从纪元存储为UTC毫秒的日期。我从NoSQL数据源（来自MongoDB的JSON）提取的架构的目标日期为：

|-- dateCreated: struct (nullable = true)

||-- $date: long (nullable = true)

完整的架构如下：

scala> accEvt.printSchema
root
 |-- _id: struct (nullable = true)
 |    |-- $oid: string (nullable = true)
 |-- appId: integer (nullable = true)
 |-- cId: long (nullable = true)
 |-- data: struct (nullable = true)
 |    |-- expires: struct (nullable = true)
 |    |    |-- $date: long (nullable = true)
 |    |-- metadata: struct (nullable = true)
 |    |    |-- another key: string (nullable = true)
 |    |    |-- class: string (nullable = true)
 |    |    |-- field: string (nullable = true)
 |    |    |-- flavors: string (nullable = true)
 |    |    |-- foo: string (nullable = true)
 |    |    |-- location1: string (nullable = true)
 |    |    |-- location2: string (nullable = true)
 |    |    |-- test: string (nullable = true)
 |    |    |-- testKey: string (nullable = true)
 |    |    |-- testKey2: string (nullable = true)
 |-- dateCreated: struct (nullable = true)
 |    |-- $date: long (nullable = true)
 |-- id: integer (nullable = true)
 |-- originationDate: struct (nullable = true)
 |    |-- $date: long (nullable = true)
 |-- processedDate: struct (nullable = true)
 |    |-- $date: long (nullable = true)
 |-- receivedDate: struct (nullable = true)
 |    |-- $date: long (nullable = true)

我的目标是按照以下方式编写查询：

SELECT COUNT(*) FROM myTable WHERE dateCreated BETWEEN [dateStoredAsLong0] AND [dateStoredAsLong1]

到目前为止，我的过程是：

scala> val sqlContext = new org.apache.spark.sql.SQLContext(sc)
sqlContext: org.apache.spark.sql.SQLContext = org.apache.spark.sql.SQLContext@29200d25

scala> val accEvt = sqlContext.jsonFile("/home/bkarels/mongoexport/accomplishment_event.json")

...
14/10/29 15:03:38 INFO SparkContext: Job finished: reduce at JsonRDD.scala:46, took 4.668981083 s
accEvt: org.apache.spark.sql.SchemaRDD = 
SchemaRDD[6] at RDD at SchemaRDD.scala:103

scala> accEvt.registerAsTable("accomplishmentEvent")

（此时，以下基准查询成功执行）

scala> sqlContext.sql("select count(*) from accomplishmentEvent").collect.foreach(println)
...
[74475]

现在，我无法理解的巫毒教徒是如何形成我的select语句来推断日期。例如，以下代码执行w / o错误，但返回零，而不是应有的所有记录数（74475）。

scala> sqlContext.sql("select count(*) from accomplishmentEvent where processedDate >= '1970-01-01'").collect.foreach(println)
...
[0]

我也尝试过一些丑陋的事情，例如：

scala> val now = new java.util.Date()
now: java.util.Date = Wed Oct 29 15:05:15 CDT 2014

scala> val today = now.getTime
today: Long = 1414613115743

scala> val thirtydaysago = today - (30 * 24 * 60 * 60 * 1000)
thirtydaysago: Long = 1416316083039


scala> sqlContext.sql("select count(*) from accomplishmentEvent where processedDate <= %s and processedDate >= %s".format(today,thirtydaysago)).collect.foreach(println)

按照建议，我选择了一个命名字段以确保其有效。所以：

scala> sqlContext.sql("select receivedDate from accomplishmentEvent limit 10").collect.foreach(println)

返回：

[[1376318850033]]
[[1376319429590]]
[[1376320804289]]
[[1376320832835]]
[[1376320832960]]
[[1376320835554]]
[[1376320914480]]
[[1376321041899]]
[[1376321109341]]
[[1376321121469]]

然后扩展以尝试获得某种日期，我已经尝试过：

scala> sqlContext.sql("select cId from accomplishmentEvent where receivedDate.date > '1970-01-01' limit 5").collect.foreach(println)

结果错误：

java.lang.RuntimeException: No such field date in StructType(ArrayBuffer(StructField($date,LongType,true)))
...

在字段名前加上$建议的前缀也会导致另一种错误：

scala> sqlContext.sql("select cId from accomplishmentEvent where receivedDate.$date > '1970-01-01' limit 5").collect.foreach(println)
java.lang.RuntimeException: [1.69] failure: ``UNION'' expected but ErrorToken(illegal character) found

select actualConsumerId from accomplishmentEvent where receivedDate.$date > '1970-01-01' limit 5

显然，我不知道如何选择以这种方式存储的日期-有人可以帮我填补这一空白吗？

我对Scala和Spark都比较陌生，因此如果这是一个基本问题，请原谅我，但是我在论坛和Spark文档上的搜索都变成了空白。

谢谢你。