What is addScalar in hibernate?
In this case, Hibernate uses ResultSetMetadata to find column details and returns the list of Object arrays. But, excessive use of ResultSetMetadata may result in poor performance, and this is where the addScalar() method is useful. By using addScalar() method, we can prevent Hibernate from using ResultSetMetadata.
What does addScalar do in below code?
addScalar is an information of returnType for a given key in SQL query. Example: Query a = new SqlQuery(“Select username as un from users where …”); a. addScalar(“un”, String);
What is add scalar?
With scalar addition, all you have to do is add your values together. You don’t have to worry about anything else. In physics, both mass and charge are scalar quantities, so you can use scalar addition with both of these. This means that all you have to do is add the values for each object and you’ll find the total.
What is Setresulttransformer in hibernate?
Hibernate’s ResultTransformers provide various ways to map the result of your query to different data structures. They were commonly used in Hibernate 4, got deprecated in Hibernate 5 and will be replaced by a functional interfaces in Hibernate 6.
What is hibernate bag collection?
Advertisements. A Bag is a java collection that stores elements without caring about the sequencing, but allow duplicate elements in the list. A bag is a random grouping of the objects in the list. A Collection is mapped with a element in the mapping table and initialized with java.
How are two scalars multiplied?
Scalar multiplication involves multiplying a given quantity by a scalar quantity. If the given quantity is scalar, the multiplication yields another scalar quantity. But, if the quantity is a vector, multiplication with a scalar gives a vector output.
What is result transformer?
Result transformers as the name suggest they are used to transform the results returned by our hibernate query to a specific format or I would say to a bean or a map. Normally, when you query for data in hibernate it returns a domain object in that case we may not find much use of Result Transformers.
What is criteria Distinct_root_entity?
setResultTransformer(Criteria. DISTINCT_ROOT_ENTITY); This statement is executed ex-post. Once the SQL query from DB engine is returned and Hibernate iterates the result set to convert that into list of our entities.
Which Hibernate collection is unordered and allows duplicates?
A is an unordered collection, which can contain duplicated elements. That means if you persist a bag with some order of elements, you cannot expect the same order retains when the collection is retrieved.
What are the collection types in Hibernate?
The persistent collections injected by Hibernate behave like ArrayList , HashSet , TreeSet , HashMap or TreeMap , depending on the interface type.
Can you multiply scalars and vectors?
A scalar, however, cannot be multiplied by a vector. To multiply a vector by a scalar, simply multiply the similar components, that is, the vector’s magnitude by the scalar’s magnitude. This will result in a new vector with the same direction but the product of the two magnitudes.