Bag Mapping

Bag Mapping

Advertisements. A Bag is a Java collection that keeps elements in a list without regard for their order yet permits duplicate entries. A bag is a haphazard collection of items on the list. A Collection is mapped with a bag> element in the mapping table and initialized with java.

A bag is a Java collection that allows duplicate entries to exist without regard for sequence. Using the bag, we may obtain information such as the number of times an object occurs in the collection.

The bag is similar to Set with duplicates in that it acts as a list without an index (you don't know what order the components are in).
In Hibernate, a Bag is an unsorted collection, and it can have duplicate components. When we keep an object in a bag, we cannot guarantee that the bag will keep its order.

q100 table="com.javatpoint.Question" class="com.javatpoint.Question">
bag name="answers" table="ans100"> bag name="answers" table="ans100"> bag name="answer
/key>key column="qid">
/element>element column="answer" type="string">element column="answer" type="string">element column="answer" type="string">element column="

Difference between list and bag.

1. In the case of a list, a sequence element is needed. In the case of the bag no need for a sequence element.

When should you utilise it? Bag

When you add an element to a sizeable uninitialized collection, bags are beneficial because they prevent the collection from becoming loaded.

Bag mapping:

If an entity contains a list of values for a property, the bag> element can map that property—the java.util.ArrayList class is used to create a bag.