Jpa why use named queries

Asked 12 years, 6 months ago. Active 9 years, 6 months ago. Viewed 21k times. Adeel Ansari Ruggs Ruggs 1, 2 2 gold badges 16 16 silver badges 25 25 bronze badges. Add a comment. Active Oldest Votes. I use named queries. There are two reasons to do so: It puts them in a more central place rather than scattered in code with random createQuery calls; and Build processes can validate the queries really useful.

Why should the central location be the model object vs the DAO that is actually using it? I forgot to mention that these named queries I typically put on the entity. If the query crosses several entities you just pick the one most relevant. Oliver Drotbohm Oliver Drotbohm Hades provides a more accessible alternative to using the plain EntityManager and is based on plain JPA, so I don't get your point really.

I think Oliver's answer and reasoning is well justified. I personally think that his example of Hades is very interesting and does answer to the question. Actually, I think I'll have a deeper glance at the framework I am also finding them awkward which is why I'm proposing the questions. Having a central place for queries makes sense for maintainability however I don't know if putting them in the model object makes sense.

The validation is actually quite nice. I use eclipse for my development and when I wrote a couple of queries I left the AS keyword off and I received errors during the build. Named queries make more sense when its gonna be complex and got executed frequently.

Objectives Use JPA named queries to perform database operations safely. Scenarios JPA named queries provide a data access and manipulation mechanism that closely ties the query content to the Java code defining the objects that the query is executing against.

Solution Example 1. Get the Newsletter Every two weeks we'll send you our latest articles along with usable insights into the state of software security. Recent Popular. Latest Tweets Tweets by Psd2Hubspot. Put your Comment Below. As you can see above, we set the name of the named query as the property name and the query as the value of the property.

If you don't want to use a properties file, you can create an orm. In addition to the above two methods, you can also declare named queries by annotating your entities with the following annotations:. Both NamedQuery and NamedNativeQuery annotations can be used separately or together on the entity class.

These annotations define the name of the query as well as the query string. If your native SQL named query returns an entity, you need explicitly indicate it by using the resultClass element. The NamedQuery annotation accepts two elements, name and query , as follows:. The NamedQuery annotation is very much similar to the Query annotation. The only difference is the former is used to define finder queries directly on the entity class, whereas the latter is used in the repository interface method.

The underlying persistence provider, Hibernate for Spring Boot, doesn't parse these queries and sends them directly to the database. This allows you to use all SQL features supported by your database. However, there are two important differences:. Just inject the EntityManager object to your controller or any other business class:. Now you call the createNamedQuery method on the EntityManager with the name of the named query you want to execute as a parameter:.

This gives you an instance of a Query interface. Now call the setParameter method on the returned interface for each binding parameter used in your query:. After specifying bind parameters, call the getSingleResult for a single result or getResultSet for multiple results method on the Query interface to execute the query:.

That's all for creating and executing a JPQL named query. You can also execute a native SQL named query in a similar way:. While creating and executing a named query using EntityManager is straightforward, it may not be the most efficient way.

Spring Data JPA allows you to reference your named queries a repository interface. If you have followed the Spring Data JPA's naming conventions, I explained before in this article, referencing a named query is very simple. All you need to do is just create a method in the repository interface with the same name as of named query, pass the correct method parameters, and specify the return type of the query method.

If the named query is a native SQL query, you also need to annotate the query method with the Query annotation and set the value of its nativeQuery attribute to true.