Entitymanager.createquery() returns which object

Viewed times. I have many queries built with createQuery method, also with parameters, like the following one: return this. I can mock all the calls' chain. If the previous point wasn't enough, the next one, some lines after, clearly set a big limitation: This feature will not work when any return type of methods included in the chain cannot be mocked for example: is a primitive or a final class. Questions How should I mock the calls on entityManager?

It seems impossible to me that I have to mock each method one by one. Is wrong to use Answers. If not, how can I handle the second example? Improve this question. Wolf A. Wolf 1, 14 14 silver badges 35 35 bronze badges. My advice would be to test the code interacting with EntityManager or any other external, low-level API using integration tests exclusively.

Trying to mock it for unit tests is a waste of time, and queries are only reliably tested using integration tests anyway. Why not test against a database, e. The "unit" in "unit test" does not necessarily mean "class". Services access directly to the entityManager. I'll update the question with a code example. Note that this pattern is used in hundreds of classes, thousands of methods, on many and many projects, so it can't be changed : — A. Turing85 Because if I got right unit test not concern databases or external api calls or something like that.

But I'm asking because I have to learn, so every advice is a good start! This comes at the cost of filling the database with test data, of course. Show 1 more comment. Active Oldest Votes. Improve this answer. Christian Beikov Christian Beikov 9, 1 1 gold badge 28 28 silver badges 49 49 bronze badges.

Thank you for your answer. Criteria queries set these clauses using Java programming language objects, so the query can be created in a type-safe manner. The following code shows how to obtain a CriteriaBuilder instance using the EntityManager.

Criteria queries are constructed by obtaining an instance of the javax. CriteriaQuery interface. CriteriaQuery objects define a particular query that will navigate over one or more entities. Obtain CriteriaQuery instances by calling one of the CrtieriaBuilder. For creating type-safe queries, call the CriteriaBuilder.

The CriteriaQuery object's type should be set to the expected result type of the query. In the following code snippet, a CriteriaQuery object is created for a query that returns a string. For a particular CriteriaQuery object, the root entity of the query, from which all navigation originates, is called the query root. Create the query root by calling the from method on the CriteriaQuery instance. Criteria queries may have more than one query root.

This usually occurs when the query navigates from several entities. For queries that navigate to related entity classes, the query must define a join to the related entity by calling one of the From. Path objects are used in the select and where clauses of a Criteria query, and can be query root entities, join entities, or other Path objects.

The Path. The argument to the get method is the corresponding attribute of the entity's Metamodel class. The attribute can either be a single-valued attribute specified by SingularAttribute in the Metamodel class or a collection-valued attribute specified by one of CollectionAttribute , SetAttribute , ListAttribute , or MapAttribute.

This query returns the names of all the pets in the data store. The results of a query can be restricted on the CriteriaQuery object according to conditions set by calling the CriteriaQuery.

The where method evaluates instances of the Expression interface to restrict the results according to the conditions of the expressions. Expression instances are created using methods defined in the Expression and CriteriaBuilder interfaces.

The CriteriaBuilder interface defines additional methods for creating expressions. These methods correspond to the arithmetic, string, date, time, and case operators and functions of JPQL. Tests whether the first numeric expression is greater than or equal to the second numeric expression. Tests whether the first numeric expression is less than or equal to the second numeric expression. Multiple conditional predicates can be specified by using the compound predicate methods of the CriteriaBuilder interface.

For queries that return more than one result, it's often helpful to organize those results. The CriteriaQuery interface defines the orderBy method to order query results according to attributes of an entity. The canonical reference for building a production grade API with Spring. In this short tutorial, we'll see how to return multiple different entities in JPA Query. First, we'll create a simple code example containing a few different entities. Then, we'll explain how to create a JPA Query that returns multiple different entities.

Finally, we'll show a working example in Hibernate's JPA implementation. Before we explain how to return multiple entities in a single Query, let's build an example that we'll work on. We'll create an app that allows its users to buy subscriptions for specific TV channels. It consists of 3 tables: Channel , Subscription , and User. It consists of 3 fields that are mapped to corresponding columns. The first and the most important one is the id, which is also the primary key.

Last but not least, there is also a subscriptionId column. It'll be used to create a relation between a channel and a subscription it belongs to. One channel can belong to different subscriptions. It's even simpler than the first one.