How do I use JPA queries in Spring Boot?

How do I use JPA queries in Spring Boot?

You can use JPA queries in Spring Boot by defining repository interfaces that extend JpaRepository. This allows you to perform CRUD operations easily.

Can you give me an example of a JPA query?

Sure! For instance, if you have an entity called 'User', you can create a method in your repository like 'findByLastName(String lastName)' to fetch users by their last name.

What if I want to use a custom query?

You can use the @Query annotation to define a custom JPQL or SQL query. For example: @Query("SELECT u FROM User u WHERE u.age > ?1") to find users older than a certain age.

Are there any performance considerations I should be aware of?

Yes, be mindful of the N+1 query problem and consider using fetch joins or batch fetching to optimize performance.