read_operation_notes.md

Read operations

Hierarchy

At the top of read operation results stands ReadResult[_]. It's separated into 2 types:

• QueryResult[_]
• GroupedResult[_]

1. QueryResult[_] used to represent simply select request without GROUP BY clause. For example SELECT * FROM db.measurement. To extract query request result from ReadResult, simple execute .queryResult on ReadResult.

2. GroupedResult[_] used to represent result of query with GROUP BY clause. Can be received by executing .groupedResult.

It's support only in single query methods as (readJs, read). Bulk methods return QueryResult only.

For more details see.

API

At the moment only untyped method exist. The base one is:

db.readJs("SELECT * FROM measurement")
res0: Future[ReadResult[JsArray]] // where JsArray it's influx point representation

You can execute multiple query's in one request:

db.bulkReadJs(Seq("SELECT * FROM measurement", "SELECT * FROM measurement1"))
res0: Future[ReadResult[Seq[JsArray]]]

The next one it's typed method, for using it you need define your own InfluxReader[T] and add it implicitly to scope.

case class FakeEntity(firstName: String, lastName: String, age: Int)

implicit val rd = new InfluxReader[FakeEntity] {
    def read(js: JsArray): FakeEntity = {
        // parsing
    }
}

And then just use it

db.read[FakeEntity]("SELECT * FROM measurement")
res0: Future[ReadResult[FakeEntity]]

To avoid boilerplate code, and headache. Just use Macros.