It's necessary to declare an
Identity column in each class while developing with hibernate. Sometimes, when we need to declare a primary key as a combination of multiple columns, we call this the composite primary key, as the primary key is composed of multiple columns. We can declare a column with the primary key constraint and also generate a composite primary key using hibernate.
Let's start with a primary key declaration:
@Id private long id;
When the preceding code is executed, hibernate creates a column with the name
idand also adds the primary key index to it. In this case,
@Columnis not required unless you want a custom column name.
To declare it as a composite primary key, we will consider creating a composite primary key using the employee's first name and phone. Therefore, the
firstNamecolumn will be duplicated...