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Manual
10

Database Schema Evolution

with default values (0, false or null). Fields in the old schema that do not have matching fields in the new ... and either the same type or a convertible type, as explained below. A matching field ... with a default value (0, false or null). The following type conversions are supported: From any numeric type
Manual
10

JPA Lifecycle Events

(added to the EntityManager). @PostPersist - after storing a new entity in the database (during commit or ... the database (during commit or flush). @PreRemove - when an entity is marked for removal in the EntityManager. @PostRemove - after deleting an entity from the database (during commit or flush). An entity
Manual
10

Database Doctor

of the Operating System, Java or ObjectDB). Copying a database file while it is open and in use. Network or I/O failure when copying, moving or transferring a database file. Transferring a database file over FTP in ASCII mode (BINARY mode should be used). Deleting an ObjectDB database recovery file or
Manual
9

Index Definition

. A PersistenceException is thrown on commit (or flush) if different entities have the same value in a unique ... with no unique constraint or a unique index if unique="true" is specified (the default is false). The optional ... . When an entity object is stored in the database every indexed field must contain either null or
Manual
9

Locking in JPA

that has to be updated or deleted is checked. An exception is thrown if it is found out that an update ... field. During commit (and flush), ObjectDB checks every database object that has to be updated or ... some ORM JPA providers) is defined in the entity class or not. Pessimistic Locking The main
Manual
9

JPA Metamodel API

Metamodel API is Metamodel. It can be obtained either by the EntityManagerFactory's getMetamodel method or ... instance: // Get a managed type (entity, embeddable or mapped super classes): ManagedType ... class when using multiple ID fields or properties. Finally, the EntityType interface adds
Result
9

Posting to ObjectDB Website - Important Instructions

ticket or as an issue. The exceptions are: Clear ObjectDB bugs, such as unexpected exception thrown ... to modify, delete or move any post at its sole discretion. 2. Content and Readability To keep your post ... To demonstrate a technical question or an issue - you may have to provide a complete runnable sample
Manual
9

GROUP BY and HAVING clauses

clause. When a GROUP BY clause exists in a JPQL query, database objects (or tuples of database objects ... (count, sum, avg, max, min) that are carried out on all the objects (or the object tuples) in the group ... which all the FROM/WHERE objects (or object tuples) are considered as one group. For example
Manual
9

Paths and Types in JPQL and Criteria API

with an instance of a user defined class (represented by a variable, parameter or prefix path expression ... must contain a persistent field (or property) with a matching name. The path expression ... , a NullPointerException is thrown on any attempt to access a field or a method via a null reference. In
Manual
9

Retrieving JPA Entity Objects

with data that is retrieved from the database (or from the L2 cache - if enabled). The new entity object ... FetchType.LAZY in either @OneToOne or @ManyToOne annotations (currently ObjectDB does not distinguish ... @OneToMany or @ManyToMany annotations (currently ObjectDB does not distinguish between the two) enables