Yawn is thin encapsulation of the Hibernate Criteria Query API in a Kotlin-friendly, type-safe and intuitive interface.

It leverages KSP to generate type-safe definitions used to power Yawn Queries.

1. Add the com.faire.yawn.version property to your Gradle properties (with the actual version in place of <VERSION>)

com.faire.yawn.version=<VERSION>

1. Add the Gradle dependencies to your build (with the actual version in place of <VERSION>)

plugins {
  id("com.faire.yawn")
}

dependencies {
  implementation("com.faire.yawn:yawn-api:<VERSION>")
}

1. Write a query!

  val yawn = Yawn(queryFactory = YourQueryFactory(...))
  val tolkienBooks = yawn.query(BookTable) { books ->
    val authors = join(books.author)
    addEq(authors.name, "J. R. R. Tolkien")
  }.list()

For more advanced details, read through our docs!

No longer guess column names and types. Begone brittle strings. No runtime errors when running your tests (or even worse, in prod).

With Yawn, it is impossible to pass in the wrong type, enforced by our friend the compiler; join paths are guaranteed to be correct; project to data classes with ease.

Easy to refactor, investigate, and safely delete fields. Analyze cascading impacts of your changes with ease.

Leverage Kotlin’s powerful introspection and refactor tools like you already do with everything else.

Use the power of the IDE that we know and love, now for queries.

Get code suggestions and hints from your coding environment.

Yawn keeps mostly the same syntax provided by Hibernate Criteria API, just adding type-safety as the cherry on top.

If you like that style of building queries, but want some type-safety on top, Yawn might just be for you.

Yawn is just a thin wrapper on top of Hibernate queries. In order to power type-safe queries, Yawn generates objects representing the metadata of each table and column related to a Hibernate entity annotated with @YawnEntity; so the migration can be completely unobtrusive and opt-in.

The generation is powered by KSP, and is composed by a set of TableDef (table definitions) that contain a set of ColumnDef (column definitions). The generate code contains the type information as generics that is necessary to make the queries safe. For example, it forces you to query columns that belong (or were joined from) to the table being queried; and it enforces the type of the values provided for comparison.

If you like Yawn, give us a star to help the project!

Have you found a bug or have a suggestion? Open an issue and we will take a look at it as soon as possible.

Do you want to contribute with a PR? Make sure to read our Contributing Guide!