25 | ObjectDB Object Database Features expressions). GROUP BY (including HAVING and aggregates). ORDER BY (including ASC, DESC). Aggregates ... attributes, grouping queries and aggregate queries) which are usually missing from Object Oriented Databases are also supported by ObjectDB. The combination of Object Database features |
25 | Paths and Types in JPQL and Criteria API all these objects (this is an aggregate query with no GROUP BY - all the objects are considered as ... expressions in the above code can be divided into two main groups: FROM variable expressions, represented by ... classes) are represented in JPQL by the following types of expressions: Variables - FROM |
22 | JPA Query Structure (JPQL / Criteria) of up to 6 clauses in the following format: SELECT ... FROM ... [WHERE ...] [GROUP BY ... [HAVING ... (update and delete queries have a slightly different form). The other JPQL clauses, WHERE, GROUP BY ... GROUP BY / HAVING (groupBy, having, count, sum, avg, min, max, ...). Criteria ORDER BY (orderBy, Order, asc, desc). |
22 | javax.persistence.criteria.CriteriaQuery entity Since: JPA 2.0 List<Expression<?>> getGroupList() Return a list of the grouping expressions. Return a list of the grouping expressions. Returns empty list if no grouping expressions have been specified. Modifications to the list do not affect the query. Returns: the list of grouping |
20 | CRUD Database Operations with JPA the results (using an ORDER BY clause) and even group results (using GROUP BY and HAVING clauses). JPQL ... a managed entity) by the persist method. The new Point objects are physically stored in the database ... objects in the database by using a simple query: Query q1 = em.createQuery("SELECT COUNT(p) FROM |
17 | FROM clause (JPQL / Criteria API) at the WHERE clause level by using a type expression. For example, in the following query, c iterates ... , and the same query can also be written as follows: SELECT c FROM Country c By default, the name ... name). The default name can be overridden by specifying another name explicitly in the @Entity's |
16 | Comparison in JPQL and Criteria API. JPQL follows the SQL notation, where Java uses its own notation (which is also in use by JDOQL ... , 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 |
16 | JPA Queries three groups. SELECT and ORDER BY elements (including tuples): FROM clause elements (representing range ... Queries are represented in JPA by the Query and TypedQuery interfaces: The JPA Query API section ... only at runtime (e.g. depending on which fields are filled by a user in a form) can be done by |
2 | [ODB1] Chapter 9 - ObjectDB Explorer Some JVM arguments can be useful. For instance, by default Java does not use more than 64MB ... . Otherwise, the required executable jar would not be found by explorer.exe. By default, running explorer.exe ... Files" menu command. By default, when the Explorer starts its opens the last used local database file |
1 | javax.jdo.JDOEntityManager to the type specified by the resultClass argument. Parameters: name - the name of a query defined in ... item, which must be assignable to the type specified by the resultClass argument. Parameters: qlString ... or is managed by another PersistenceManager. Parameters: pc - a persistent instance Since: JDO 1.0 |
