# Upgrade from 2.0-ALPHA4 to 2.0-BETA1 ## New inversedBy attribute It is now *mandatory* that the owning side of a bidirectional association specifies the 'inversedBy' attribute that points to the name of the field on the inverse side that completes the association. Example: [php] // BEFORE (ALPHA4 AND EARLIER) class User { //... /** @OneToOne(targetEntity="Address", mappedBy="user") */ private $address; //... } class Address { //... /** @OneToOne(targetEntity="User") */ private $address; //... } // SINCE BETA1 // User class DOES NOT CHANGE class Address { //... /** @OneToOne(targetEntity="User", inversedBy="address") */ private $user; //... } Thus, the inversedBy attribute is the counterpart to the mappedBy attribute. This change was necessary to enable some simplifications and further performance improvements. We apologize for the inconvenience. ## Default Property for Field Mappings The "default" option for database column defaults has been removed. If desired, database column defaults can be implemented by using the columnDefinition attribute of the @Column annotation (or the approriate XML and YAML equivalents). Prefer PHP default values, if possible. ## Partial Objects xxx ## XML Mapping Driver The 'inheritance-type' attribute changed to take last bit of ClassMetadata constant names, i.e. NONE, SINGLE_TABLE, INHERITANCE_TYPE_JOINED ## YAML Mapping Driver The way to specify lifecycle callbacks in YAML Mapping driver was changed to allow for multiple callbacks per event. The Old syntax ways: [yaml] lifecycleCallbacks: doStuffOnPrePersist: prePersist doStuffOnPostPersist: postPersist The new syntax is: [yaml] lifecycleCallbacks: prePersist: [ doStuffOnPrePersist, doOtherStuffOnPrePersistToo ] postPersist: [ doStuffOnPostPersist ] ## PreUpdate Event Listeners Event Listeners listening to the 'preUpdate' event can only affect the primitive values of entity changesets by using the API on the `PreUpdateEventArgs` instance passed to the preUpdate listener method. Any changes to the state of the entitys properties won't affect the database UPDATE statement anymore. This gives drastic performance benefits for the preUpdate event.