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The GROUP BY clause enables grouping of query results. A JPQL query with a GROUP BY clause returns properties of generated groups instead of individual objects and fields. The position of a GROUP BY ... clause. When a GROUP BY clause exists in a JPQL query, database objects (or tuples of database objects

BY c.name DESC Grouping ( GROUP BY ) Order The ORDER BY clause is always the last in the query processing chain. If a query contains both an ORDER BY clause and a GROUP BY clause the SELECT clause receives groups rather than individual objects and ORDER BY can order these groups . For example: SELECT c

superclasses) can be classified into the following five groups : Transient fields Persistent fields Inverse (Mapped By ) fields Primary key (ID) fields Version field The first three groups (transient ... two groups (primary key and version fields) can only be used in entity classes. Primary key fields

. The SELECT clause counts all these objects (this is an aggregate query with no GROUP BY - all the objects ... can be divided into two main groups : FROM variable expressions , represented by subinterfaces of From ... classes) are represented in JPQL by the following types of expressions: Variables - FROM

JOIN and JOIN FETCH ). WHERE (with both JPQL and JDOQL expressions). GROUP BY (including HAVING ... , derived 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

;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 ... ;( where ). Criteria GROUP BY / HAVING  ( groupBy , having , count , sum , avg , min , max

group should include fields that are needed often and are relatively small. By default, the group ... and references to user defined classes are excluded by default. The default-fetch- group attribute ... file. The metadata is used first by the JDO Enhancer, and later by the JDO

the default fetch group should not be accessed by this method. void jdoPreDelete() Called ... store methods and code. Only the state of the object as reflected by its persistent fields is stored. Persistent fields, by default, are all the fields that are not defined as static , final or

.jar my.odb Some JVM arguments can be useful. For instance, by default Java does not use ... . Otherwise, the required executable jar would not be found by explorer.exe. By default, running explorer.exe ... " menu command. By default, when the Explorer starts its opens the last used local database file

. Parameters: group a - comma-delimited list of expressions, optionally followed by the "having" keyword and a boolean expression Since: JDO 2.0 ... JDO Method in javax.jdo.Query void setGrouping (   String  group ) Set the grouping expressions, optionally including a "having" clause. When grouping is specified, each result