JarCastingaws-dynamodb-scala 
Scala client for Amazon DynamoDB
How to use
Add a following dependency into your build.sbt at first.
libraryDependencies += "jp.co.bizreach" %% "aws-dynamodb-scala" % "0.0.9"
Then you can use aws-dynamodb-scala in your code.
import jp.co.bizreach.dynamodb4s._
import awscala.dynamodbv2.DynamoDB
// for local environment
implicit val db = DynamoDB.local()
// for AWS environment
implicit val db = DynamoDB.apply(accessKeyId = "xxx", secretAccessKey = "xxx")
Create table definition as below:
object Members extends DynamoTable {
val table = "members"
val country = DynamoHashKey[String]("country")
val id = DynamoRangeKey[Int]("id")
val name = DynamoAttribute[String]("name")
val age = DynamoAttribute[Int]("age")
val company = DynamoAttribute[String]("company")
}
// Case class is optional
case class Member(
val country: String,
val id: Int,
val name: String,
val age: Int,
val company: Option[String]
)
Put
// Put by case class
Members.put(Member("Japan", 1, "Naoki Takezoe", 30, Some("BizReach")))
// Update only specified properties
Members.putAttributes("Japan", 1){ t =>
t.name -> "Takako Shimamoto" :: t.age -> 25 :: Nil
}
Query
// Query with case class mapping
val list: Seq[Member] = Members.query.filter { t =>
t.country -> DynamoDBCondition.eq("Japan") :: t.id -> DynamoDBCondition.eq(1) :: Nil
}.list[Member]
// Query with manual mapping
val list: Seq[(String, Int)] = Members.query
.select { t => t.name :: t.age :: Nil }
.filter { t => t.country -> DynamoDBCondition.eq("Japan") :: t.id -> DynamoDBCondition.eq(1) :: Nil }
.limit(100000)
.map { (t, x) =>
(x.get(t.name), x.get(t.age))
}
Secondary index
object Members extends DynamoTable {
val table = "members"
val id = DynamoHashKey[Int]("id")
val country = DynamoRangeKey[String]("country")
val name = DynamoAttribute[String]("name")
val age = DynamoAttribute[Int]("age")
val company = DynamoAttribute[String]("company")
object companyIndex extends DynamoTable.SecondaryIndex {
val index = "companyIndex"
val country = DynamoHashKey[String]("country")
val company = DynamoRangeKey[String]("company")
}
}
val list: Seq[Member] = Members.query.filter2(_.companyIndex){ t =>
t.country -> DynamoDBCondition.eq("Japan") :: t.company -> DynamoDBCondition.eq("BizReach") :: Nil
}.list[Member]
Scan
Members.scan.filter("company = :company", "company" -> "BizReach").as[Member]{ x =>
println(x)
}
