querydsl-jpa

Querydsl unified Queries for Java. Querydsl is compact, safe and easy to learn.

This module provides JPA integration.

NOTE: this module doesn’t provide JPA support to your application. Check out the hbm module for JPA support.

usage

• Create a querydsl-jpa.activator file in the src/etc/ directory.

• Open a terminal and type: mvn clean compile

• Generated classes will be placed inside the target/generated-sources directory.

Of course, you need to define some entities and have JPA in your classpath. The hibernate module gives you JPA support.

profile activation

Just create a src/etc/querydsl-jpa.activator file. The file contents doesn’t matter, it just needs to be present.

The file src/etc/querydsl-jpa.activator will trigger a maven profile that does all this for you.

example

Here is an example with hibernate:

• Source code:

import org.jooby.hbm.Hbm;

class App extends Jooby {
  {
    // configure Hbm
    use(new Hbm(Pet.class));
    ...
  }
}

package domain;

@Entity
class Pet {
  @Id
  private int id;

  private String name;
}

• Write the src/etc/querydsl-jpa.activator file.

• Open a console and type: mvn clean compile

• Find the generated source code at: target/generated-sources

• Using JPAQuery:

import static domain.QPet.pet;
import com.querydsl.jpa.impl.JPAQuery;
import javax.persistence.EntityManager;

{
  // configure Hbm
  use(new Hbm(Pet.class));

  get("/pets/:name", req -> {
    String name = req.param("name").value();
    EntityManager em = require(EntityManager.class);

    return new JPAQuery(em)
      .from(pet)
      .where(pet.name.like(name))
      .fetch();
  })
}

Querydsl will find all your entities (classes annotated with @Entity) and generates a class with the same name, but prefixed with Q, like QPet.