php - What is the difference between inversedBy and mappedBy?

Question

I am developing my application using Zend Framework 2 and Doctrine 2.

While writting annotations, I am unable to understand the difference between mappedBy and inversedBy.

When should I use mappedBy?

When should I use inversedBy?

When should I use neither?

Here is an example:

 /**
 *
 * @ORMOneToOne(targetEntity="custModEntityPerson", mappedBy="customer")
 * @ORMJoinColumn(name="personID", referencedColumnName="id")
 */
protected $person;

/**
 *
 * @ORMOneToOne(targetEntity="AuthEntityUser")
 * @ORMJoinColumn(name="userID", referencedColumnName="id")
 */
protected $user;

/**
 *
 * @ORMManyToOne (targetEntity="custModEntityCompany", inversedBy="customer")
 * @ORMJoinColumn (name="companyID", referencedColumnName="id")
 */
protected $company;

I did a quick search and found the following, but I am still confused:

• example 1
• example 2
• example 3

Answer 1

• mappedBy has to be specified on the inversed side of a (bidirectional) association
• inversedBy has to be specified on the owning side of a (bidirectional) association

from doctrine documentation:

• ManyToOne is always the owning side of a bidirectional assocation.
• OneToMany is always the inverse side of a bidirectional assocation.
• The owning side of a OneToOne assocation is the entity with the table containing the foreign key.

See https://www.doctrine-project.org/projects/doctrine-orm/en/latest/reference/unitofwork-associations.html