ObjectDB ObjectDB

Internal Website Search

1-10 of 200 resultsRefresh
110

JPA Query Structure (JPQL / Criteria)

clause declares one or more query variables (also known as identification variables). Query variables are similar to loop variables in programming languages. Each query variable represents iteration over objects in the database. A query variable that is bound to an entity class is referred to as
100

JPA Criteria API Queries

the built query. Then a Root instance is created to define a range variable in the FROM clause. Finally, the range variable, c, is also used in the SELECT clause as the query result expression ... The JPA Criteria API provides an alternative way for defining JPA queries, which is mainly useful
97

DELETE Queries in JPA/JPQL

. Applying changes to the database by calling the commit method. JPQL DELETE queries provide an alternative way for deleting entity objects. Unlike SELECT queries, which are used to retrieve data from the database, DELETE queries do not retrieve data from the database, but when executed, delete specified
96

Criteria Query From Elements

The interfaces in this group are in use for setting a criteria query FROM clause. Criteria Query Variables The FROM clause in JPA queries (as in SQL) defines the query variables. Query variables are represented in criteria queries by descendant interfaces of the From interface: Range variables
96

FROM clause (JPQL / Criteria API)

The FROM clause declares query identification variables that represent iteration over objects in the database. A query identification variable is similar to a variable of a Java enhanced for loop in a program, since both are used for iteration over objects. Range Variables Range variables are query
96

UPDATE SET Queries in JPA/JPQL

. Applying changes to the database by calling the commit method. JPQL UPDATE queries provide an alternative way of updating entity objects. Unlike SELECT queries, which are used to retrieve data from the database, UPDATE queries do not retrieve data from the database, but when executed, update
86

JPA Queries

variables, join and fetch): Other criteria query expressions (for all the query clauses): ... Queries are represented in JPA by the Query and TypedQuery interfaces: The JPA Query API section ... these interfaces to build and run JPQL queries. The TypedQuery interface (or alternatively the older Query
17

[ODB1] Chapter 7 - JDOQL Queries

all the elements that can be used in a JDOQL query filter, except for parameters and variables ... queries with more than three parameters. 7.4 Query Variables There are two types of variables in JDOQL: Bound variables, whose main role is in querying collection fields Unbound variables, which serve
10

declareVariables(variables)

Method javax.jdo.Query void declareVariables( String variables ) Declare the unbound variables to be used in the query. Variables might be used in the filter, and these variables must be declared with their type. The unbound variable declaration is a String containing one or more unbound variable
9

Constants.OPTION_UNCONSTRAINED_QUERY_VARIABLES

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

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