Tydal 3 is a typesafe PostgreSQL DSL for Scala 3 built on top of Skunk.
If you're looking for a Scala 2 compatible version of this library, please refer to Tydal.
Tydal 3 is essentially a DSL to build Postgres queries and commands
that could be used instead of the classic Skunk sql and fr String interpolations.
The main advantage of going through the Tydal DSL is type-safety, as a bunch of common mistakes can be prevented at compile time such as referring to a non-existing table or field, comparing fields of unrelated types, or decoding the results of a query into an incompatible data structure.
Here's a basic example:
import cats.effect.IO
import skunk.{Query, Session}
import tydal.*
object artist extends TableSchema[
"artist",
(
"id" :=: uuid,
"name" :=: varcharOf[128],
"genres" :=: array[varchar]
)
]
val query =
Select
.from(artist as "a")
.take(_("a").*)
.where(x => (x("a", "genres") contains "genre?") and (x("a", "name") like "name?"))
.sortBy(_("a", "name"))
.limit("limit?")
.compile
// For more information on how to initiate a Session
// or to run a query please refer to https://tpolecat.github.io/skunk/
def runQuery(session: Session[IO]): IO[List[(java.util.UUID, String, Arr[String])]] =
session.prepareR(query).use(_.stream((
"genre?" ~~> "Psychedelic",
"name?" ~~> "%Floyd",
"limit?" ~~> 50
), 10).compile.toList)Tydal supports a fair amount of PostgreSQL, and most common queries can be expressed through the DSL,
but not everything is or can be supported, of course.
For a complete list of supported features please refer to this documentation.
You can find some examples here.
The project is open source, and you're very welcome to contribute!
$ docker-compose up -d
$ sbt testStep 1. Add the JitPack repository to your build file
resolvers += "jitpack" at "https://jitpack.io"
Step 2. Add the dependency
libraryDependencies += "com.github.epifab" % "tydal3" % "0.3"