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Entity can be found by find() but not by query

and sometimes we don't get the entity by query. Have you an idea what happens here? btc_es BTC EmbeddedSystems

Mapped By Fetch is very Slow

Well ! I think i pointed out a HUGE performance issue with mapped-by attribute (yeah ... , go the MyEntity class and remove "mapped-by". You obtain 1 second max of query fetch. So my performance issue ... .ALL,mappedBy = "myEntity") // Test by adding / remove "mappedBy" public MyEntityChild getEntityChild

Mapped by fields are not initialized by JOIN FETCH in queries

As demonstrated in this forum thread, a mapped by collection field with lazy fetch mode is not initialized in results of a query that uses JOIN FETCH on that collection field (when enhancement is used). support Support Build 2.4.1_06 fixes this issue (fields are now initialized and the test in

Strings in JPQL and Criteria Queries

). To match an actual underscore or percent character it has to be preceded by an escape character ... to 'UK'. By default, space characters are removed, but any other character can also be specified: TRIM ... ); As demonstrated above, most methods are overloaded in order to support optional arguments

What are the main benefits of using ObjectDB?

By using ObjectDB you can reduce development time and costs and improve your application ... fields can be stored by ObjectDB simply as part of the containing object. Relational databases lack that ability and require multiple tables, multiple records and join operations in order to support


selection item Since: JPA 2.0 Order asc( Expression<?> x) Create an ordering by the ascending value of the expression. Create an ordering by the ascending value of the expression. Parameters: x - expression ... Order desc( Expression<?> x) Create an ordering by the descending value of the expression. Create


. If the ordering element is not specified for an entity association, ordering by the primary key ... of basic type, the ordering will be by value of the basic objects and the property or field name is not ... { ... @ManyToMany(mappedBy="students") @OrderBy // ordering by primary key is assumed


for ordering that is visible as persistent state and maintained by the application. The OrderBy ... a column that is used to maintain the persistent order of a list. The persistence provider is responsible for maintaining the order upon retrieval and in the database. The persistence provider

JPA Tutorials

Tutorial Only basic Java experience is required in order to follow this tutorial. Web Application ... application: Spring MVC and JPA Maven Projects for Download The tutorials provide step by step

JDO Internal Callbacks

The following interfaces can be implemented by persistence capable classes in order to response to JDO lifecycle events:

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.

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