 32 | Fetch Retrieval of an entity object from the database might cause automatic retrieval of additional ... using a lazy fetch type:
@Entity
class Employee {
:
@ManyToOne(fetch=FetchType.LAZY ... with the FetchType.LAZY fetch policy is initialized to reference a new managed hollow object (unless |
24 | know that I can express one level of eager fetch in JPQL as follows:
SELECT c FROM C JOIN FETCH c.bList WHERE c.id=:id But when I attempt to take it to the 2nd level:
SELECT c FROM C JOIN FETCH c.bList JOIN FETCH c.bList.aList WHERE c.id=:id I get an error along the lines of:
Invalid fetch path |
21 | for detachment (DETACH_LOAD_FIELDS and DETACH_UNLOAD_FIELDS) and the active fetch groups determine the scope of fetching for the graph of instances reachable from the pc parameter. The state of fields in ... ) and the active fetch groups determine the scope of fetching for the graph of instances reachable from the pcs |
21 | javax.jdo Interface FetchPlan Fetch groups are activated using methods on this interface ... and setDetachmentOptions. Specifies that fields that are not loaded but are in the current fetch ... and setDetachmentOptions. Specifies that fields that are loaded but not in the current fetch plan |
20 | fetch doi.metadata metadata
left join fetch metadata.titles titles
left join fetch metadata.creators creators
left join fetch metadata.descriptions descriptions
left join fetch metadata.publishers publishers
left join fetch metadata.contributors contributors
left join fetch metadata.dates |
20 | Hello, I'm a little bit confused about a left join fetch behaviour. In this test case, i try to fetch my 3 children using a left join fetch. But my collection is null after closing the em. It was expected to be fetched before closing the em, no ? In fact, that is the objective of the fetch purpose |
19 | " />
< fetch hollow="true" />
The hollow attribute of the < fetch> element (whose value is "true" or "false |
19 | . Lazy/Eager Loading Automatic pre-loading optimizations. Configurable JPA eager/lazy fetch and JPA query FETCH JOIN. Configurable JDO fetch groups. Ease of Use and Learning ObjectDB is very simple ... (including INNER JOIN, LEFT OUTER JOIN and JOIN FETCH). WHERE (with both JPQL and JDOQL expressions |
19 | . Lazy/Eager Loading Automatic pre-loading optimizations. Configurable JPA eager/lazy fetch and JPA query FETCH JOIN. Configurable JDO fetch groups. Ease of Use and Learning ObjectDB is very simple ... (including INNER JOIN, LEFT OUTER JOIN and JOIN FETCH). WHERE (with both JPQL and JDOQL expressions |
19 | Automatic pre-loading optimizations. Configurable JPA eager/lazy fetch and JPA query FETCH JOIN. Configurable JDO fetch groups. Ease of Use and Learning ObjectDB is very simple to use and is easier ... OUTER JOIN and JOIN FETCH). WHERE (with both JPQL and JDOQL expressions). GROUP BY (including HAVING |