scala_mongodb驱动的问题

scala mongodb groupby 多个字段

今天同事问groupby多个字段是怎么写的

然后上$group (aggregation)
看了下，发现要写表达式，看了这篇文章MongoDB aggregate 运用篇个人总结，发现要像如下写：


多列group，根据name和status进行多列

db.collection.aggregate([

{$group:{_id:{name:"$name",st:"$status"},count:{$sum:1}}}

]);

那么代码中应该怎么写呢，研究了半天，看到这篇文章MongoDB getCollection with a specific document class

发现我们得从定义mongodbClient开始定义个codeRegistry


case class GroupByCode(name:String,code:String)  {
    // val id: String = _id.toString
  }
  private[bigdata] val personCodecProvider = Macros.createCodecProvider[GroupByCode]()
  private[bigdata] val codecRegistry = fromRegistries( fromProviders(personCodecProvider), DEFAULT_CODEC_REGISTRY )

  private[bigdata] val connectionString = new ConnectionString(utils.dbUrl)
  private[bigdata] val   options = MongoClientSettings
    .builder()
    .codecRegistry(codecRegistry)
    .clusterSettings(ClusterSettings.builder().applyConnectionString(connectionString).build())
    .connectionPoolSettings(ConnectionPoolSettings.builder().applyConnectionString(connectionString).build())
    .serverSettings(ServerSettings.builder().build()).credentialList(connectionString.getCredentialList)
    .sslSettings(SslSettings.builder().applyConnectionString(connectionString).build())
    .socketSettings(SocketSettings.builder().applyConnectionString(connectionString).build())
    .build()
  //private[bigdata] val mongoClient = MongoClient(utils.dbUrl)
  private[bigdata] val mongoClient = MongoClient(options)

然后在用的地方直接

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val groupBy = group(GroupByCode("$userType","$code"),sum("count", 1))

Await.result(prdb.aggregate(filter(Filters.and(Filters.eq("code", parkCode), Filters.gte("exitDate", date), Filters.lt("exitDate", c.getTime))) :: groupBy :: Nil).toFuture(), read_timeout)

当然mongodb-scala-driver得升级到2.0版才支持caseClassCodec

New in 2.0, the Scala driver allows you to use case classes to represent documents in a collection via the Macros helper. Simple case classes and nested case classes are supported. Hierarchical modelling can be achieve by using a sealed trait and having case classes implement the parent trait.