Using Querydsl With Spring Data JPA

The Querydsl lets us build type-safe queries using its fluent API

Somnath Musib

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Image Courtesy: Unsplash by Ignacio Amenábar

Introduction

The Querydsl is a third-party library that lets us define type-safe queries. It also makes the query generation relatively easy through its fluent DSL APIs. In general, the native SQL or the Java Persistence Query Language (JPQL) does not provide any means to validate the correctness of the queries at compile time. Any query syntax or other issues are detected at run time and cause the application to fail.

In this tutorial, we’ll look into the usage of Querydsl library that lets you do the following:

  • Validate that the entities used in the query exists and can be persisted in the database
  • Properties used in a query exists and also can be persisted
  • The SQL operators used in the query is assigned with expectant values
  • Lastly, the resultant query is correct

The Application

To demonstrate the use of Querydsl, we’ll use a Spring Boot application named Pocket. This is an extremely simple application lets us bookmark our favourite URLs along with a category. Let us browse to the https://start.spring.io and create a new Spring Boot project with the…

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Somnath Musib

4X AWS | Staff Software Engineer, Cloud Architect | Author "Spring Boot In Practice" | Find more at https://musibs.github.io