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A Scala meta-DSL to use the Datomic® database

m	Molecule
	Typesafe Scala meta-DSL for Datomic On-Prem Intuitively use your domain terms as query tokens Sync/Async APIs Model any RDBMS, Graph, Document, KV-store etc. Datalog queries for Datomic built at compile time (Molecule is not affiliated with Datomic) Read more...

	Datomic®
	Datomic official website Fully transactional, cloud-ready, distributed database Elastic scaling Built-in caching - extremely low latency Built-in auditing - query entire history of data ACID-compliant transactions Flexible and sound data model

Setup

Define and compile your domain schema

trait Person {
  val name    = oneString
  val age     = oneInt
  val address = one[Address]
}
trait Address {
  val street = oneString
}

> cd yourProjectRoot
> sbt compile

Application code

Transact data

Person.name.age.Address.street insert
  List(
    ("Lisa", 20, "Broadway"),
    ("John", 22, "Fifth Avenue")
  )

Query data

Person.name.age.Address.street.get ===
  List(
    ("Lisa", 20, "Broadway"),
    ("John", 22, "Fifth Avenue")
  )

Molecule ⟷ Datomic

Molecule talks to Datomic

⟶	Tx statements	⟶	Datomic
⟵	Tx report	⟵

⟶	Datalog	⟶
⟵	Typed data	⟵

Write powerful Datomic queries in Scala with the words of your domain:

Type-inferred Queries

Build query molecules with your domain attributes

val persons: List[(String, Int)] = Person.name.age.get

“Name and age of Persons”

Relationships

Pick attributes across namespaces

Person.name.age.Address.street.Country.name.get

“Name, age, street and country of residence”

Conditional values

Apply required values for certain attributes

Person.name("Johnson").age.Address.City.name("New York").get

“Age of Johnsons in New York” - name, age and city returned

Control output

Add an underscore to omit an attribute from the result set:

Person.name_("Johnson").age.Address.City.name_("New York").get

“Age of Johnsons in New York” - only ages returned

Logic and ranges

Apply logical options and ranges

Person.name("Dean" or "Johnson").age.<(25).Address.Country.iso2("US").get

“Young Dean and Johnsons in the US”

Insert multi-level data

Save data for multiple namespace levels in one go:

Person.name("Johnson").age(35).Address.street("5th").City.name("New York").save

“Add a 35-year-old Johnson living on 5th street in New York”

Update data

Update molecules with new data

Person(johnsonId).Address.street("Broadway").update

“Johnson now lives on Broadway”

More..

Try demo

git clone https://github.com/scalamolecule/molecule-demo.git
cd molecule-demo
sbt compile
Open in your IDE
Run app - and build new molecules…

Introduction to Datomic/Molecule
Getting started with Molecule
Setup your Molecule project