What's the difference between the name argument in @Entity and @Table when using JPA?

Question

I\'m using JPA2 and both @Entity and @Table have a name attribute, e. g.:

@Entity(name=\"Foo\")
@Table (name=\"Bar\")
         


        

Answer 1

@Table is optional. @Entity is needed for annotating a POJO class as an entity, but the name attribute is not mandatory.

If you have a class

 @Entity
 class MyEntity {}

A table with name "MyEntity" will be created and the Entity name will be MyEntity. Your JPQL query would be:

 select * from MyEntity

In JPQL you always use the Entity name and by default it is the class name.

if you have a class

 @Entity(name="MyEntityName")
 @Table(name="MyEntityTableName")
 class MyEntity {}

then a table with name MyEntityTableName is created and the entity name is MyEntityName.

Your JPQL query would be :

 select * from MyEntityName

Answer 2

The name in @Entity is for JPA-QL queries, it defaults to the class name without package (or unqualified class name, in Java lingo), if you change it you have to make sure you use this name when building queries.

The name in @Table is the table name where this entity is saved.

Answer 3

@Entity is useful with model classes to denote that this is the entity or table

@Table is used to provide any specific name to your table if you want to provide any different name

Note: if you don't use @Table then hibernate consider that @Entity is your table name by default

@Entity    
@Table(name = "emp")     
public class Employee implements java.io.Serializable { }