CODEWITHSUNDEEP
javahibernate
Zhijie Liu
Zhijie Liu

Reputation: 51

How to limit entity number using entity?

With the Persistence provider Hibernate, how to limit entity number using entity Assume we have an Address entity, how to limit we can only have 10 addresses for a user?

I want to restrict this on entity level.

Upvotes: 2

Views: 540

Answers (2)

Saravana
Saravana

Reputation: 12817

annotate the maximum number of children objects allowed using @Size annotation

@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@Size(max = 2)
private List<Child> children;

If the children exceeded the limit, it will throw below Exception during persist time

Caused by: javax.validation.ConstraintViolationException: Validation failed for classes [org.myapp.Parent] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='size must be between 0 and 2', propertyPath=childs, rootBeanClass=class org.myapp.Parent, messageTemplate='{javax.validation.constraints.Size.message}'}
]

also you can specify the min number of objects.

need to include below dependency in pom if hibernate is used

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>{hibernate.version}</version>
</dependency>

Upvotes: 2

user5622465
user5622465

Reputation:

if you are using mysql this might help you for backend(database).

 ALTER TABLE tbl_name MAX_ROWS=1000000000 AVG_ROW_LENGTH=nnn;

for front end 

List<entity> list=new ArrayList<entity>();
if(list.size()>10){
      //some condtions
     }

this way you can set the limit table rows

Upvotes: 0

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