ObjectDB ObjectDB

Internal Website Search

1-10 of 200 resultsRefresh

Null enums and IS (NOT) NULL: NullPointerException

Hello. I'm getting NullPointerException when adding %enum field% IS (NOT) NULL or == (!=) NULL in ... .exampleEnum IS NULL"); entities = query.getResultList(); } public void method ... you for this report. Comparing enum values to NULL was fixed in build 2.5.5_03. support Support

Comparison in JPQL and Criteria API

, there is also a difference in the way that NULL values are handled by these operators. Comparing NULL values The following table shows how NULL values are handled by each comparison operator. One column presents a comparison of NULL value with a non NULL value. The other column presents a comparison of two NULL

Logical Operators in JPQL and Criteria API

must be one of: TRUE, FALSE, and NULL. The following table shows how the AND operator is evaluated based on its two operands: TRUE FALSE NULL TRUE TRUE FALSE NULL FALSE FALSE FALSE FALSE NULL NULL FALSE NULL NULL represents unknown. Therefore, if one operand is NULL and the other operand is FALSE

Literals in JPQL and Criteria Queries

including NULL, boolean literals (TRUE and FALSE), numeric literals (e.g. 100), string literals (e.g ... and never replaced. The NULL literal The NULL literal represents a null value, similarly to null in Java and SQL. Since JPQL is case insensitive, NULL, null and Null are equivalent. Notice

Paths and Types in JPQL and Criteria API

through a NULL value The following query retrieves country names with their capital city names: SELECT ... is evaluated to NULL and c.capital.name is an attempt to navigate from a NULL value. In Java, a NullPointerException is thrown on any attempt to access a field or a method via a null reference. In JPQL

com.objectdb.o.InternalException: null

PersistableObject {     @OneToOne(mappedBy = "spouse")     private Customer spouse = null;     private Date dateOfBirth = null;     private String firstName = null;     private String lastName = null;     private String personalNumber = null;     private String street = null;     private String

Once served to JSF page via @EJB query bean, many list fields are null (but same query ok after fresh persist in @PostConstruct)

via a querying @EJB gives many fields null (and not even empty, I mean truly null). In the following ... @OneToOne relationship fields that likewise become null: private List<Element> ownedElements = new ... []: Created: com.greensoft.entity.test.TestDeepValues [null](TEST: test deep values) INFO: RequestBean


Static Field javax.jdo.Constants String OPTION_NULL_COLLECTION "javax.jdo.option.NullCollection" Since: JDO 2.1 See Also: PersistenceManagerFactory.supportedOptions()


Enum Constant javax.jdo.annotations.ForeignKeyAction NULL Since: JDO 2.1

[ODB1] Chapter 4 - JDO Metadata

" embedded="false" /> <field name="f7" null-value="exception" /> <field name="f8" null-value="none" /> <field name="f9" null-value="default" /> </class> </package> </jdo ... demonstrated by field f6. null-value (exception | none | default) The null-value attribute is also intended

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

Need Help?

  1. Search ObjectDB website
  2. Read the FAQ
  3. Follow the Tutorials
  4. View or post in the forum
  5. Search or file an issue
  6. Contact support