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Recent questions tagged jpa

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jpa - How to make a CriteriaBuilder join with a custom "on" condition?

I want make a query where I join 2 tables, using the CriteriaBuilder. In MySQL the query I'm trying to make ... query like in the first example? See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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402 views

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jpa 2.0 - What is the difference between @Inject and @EJB

I'm currently learning the new Java EE 6 component models and am confused with the latest dependency injection ... 6 new component model. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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529 views

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jpa - Java entity - why do I need an empty constructor?

This might sound stupid to you, but why do I need to define an empty constructor in my @Entitys? Every ... this empty constructor seems useless. See Question&Answers more detail:os...

asked Oct 24, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.5k views

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jpa - How to properly cast string to number with JPA2 Criteria API?

I am trying to write a query with subselect where a string is cast to a long. I'm probably missing something? ... m using Hibernate 3.6.8-Final See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.1k views

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jpa - java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to

why java.lang.ClassCastException is triggered in my program ? java.lang.ClassCastException: [Ljava.lang.Object; cannot be ... ? Thanks a lot!!! See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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479 views

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jpa criteriabuilder join maps

I have the following criteria builder query CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<Object> ... AbstractPathImpl.java:261) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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441 views

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jpa - Hibernate Best Practices: Avoiding Many-To-Many and 'exotic' relationships

The hibernate best practices states that many-to-many associations are rare and should be avoided. Do not use ... User is not so practical. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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553 views

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jpa 2.0 - JPA Criteria select all instances with max values in their groups

Is there a way to write with JPA 2 CriteriaBuilder the equivalent of the following query? select * from season ... s1.contest=s2.contest ) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.3k views

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jpa - Schema-validation: missing table [game]

I think it may be possible dupplicate of this: Schema-validation: missing table [hibernate_sequences] but I can't ... = startSessions; } } See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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512 views

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jpa - @OneToOne unidirectional and bidirectional

I have two examples that first is @OneToOne unidirectional mapping and second bidirectional. In unidirectional ... act like unidirectional? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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834 views

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jpa 2.0 - Cannot make @ManyToOne relationship nullable

I have a many-to-one relationship that I want to be nullable: @ManyToOne(optional = true) @JoinColumn(name = " ... case? Thank you in advance. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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523 views

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jpa 2.0 - JPA - Criteria API and EmbeddedId

I want to use criteria to make the following query. I have an Entity with EmbeddedId defined: @Entity @Table( ... annotations? Thanks!. Mauro. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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498 views

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jpa - Should Hibernate be able to handle overlapping foreign keys?

I have a table that has two foreign keys to two different tables with both foreign keys sharing one column: CREATE ... spec? Is this a bug? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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596 views

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jpa - Is it possible to use Hibernate with PostgreSql's JSONB data type?

Hibernate 5 does not support the PostgreSQL jsonb data type by default. Is there any way to implement jsonb ... of using jsonb with Hibernate? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.3k views

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jpa - IntelliJ IDEA highlights @Entity class names with "Cannot resolve symbol" in JPQL

IntelliJ IDEA highlights persistent @Entity class names with "Cannot resolve symbol" in red in JPQL which is ... project does not use) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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880 views

1 answer

jpa - How can I use DB side default value while use Hibernate save?

I have a column in DB with default value as sysdate. I'm looking for a way to get that default ... annotation-based configuration. Any advice? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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452 views

1 answer

jpa - Getting a reference to EntityManager in Java EE applications using CDI

I'm using Java EE 7. I would like to know what is the proper way to inject a JPA EntityManager into an ... but that's not the point :) See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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458 views

1 answer

jpa 2.0 - How can I make a JPA application access different databases?

I'm writing a Java SE (desktop) application that has to access different databases all of which will have ... the desktop application. Thanks. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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704 views

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jpa - Persist java.time.Instant (JDK8) with JPA2/Hibernate

Neither JPA nor Hibernate currently support the new date/time classes brought by JSR-310 in JDK8 (JPA ticket, ... there better options? Thanks. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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396 views

1 answer

jpa - createEntityManager throws java.lang.NullPointerException at org.hibernate.engine.transaction.internal.jta.JtaStatusHelper.getStatus

I'm getting this stack trace when I deploy my hibernate app java.lang.NullPointerException at org.hibernate.engine. ... () giving the NPE? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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582 views

1 answer

jpa - Is it possible to output generated SQL using EclipseLink without having to increase log verbosity?

I want to output the SQL generated by EclipseLink to the console, during development. However, I could only do ... FINE (like Hibernate does)? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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587 views

1 answer

jpa - @UniqueConstraint annotation in Java

I have a Java bean. Now, I want to be sure that the field should be unique. I am using the following code: ... Note: I am using play framework. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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1.0k views

1 answer

jpa - How do I do a "deep" fetch join in JPQL?

I don't think I will ever fully understand fetch joins. I have a query where I'm attempting to eagerly "inflate" ... t see any way to do this. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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773 views

1 answer

jpa 2.0 - Hibernate inserts duplicates into a @OneToMany collection

I have a question concerning Hibernate 3.6.7 and JPA 2.0. Consider following entities (some getters and ... am I missing something? Thanks See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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608 views

1 answer

jpa - How to use Spring AbstractRoutingDataSource with dynamic datasources?

I am working in a project using Spring, Spring Data JPA, Spring Security, Primefaces... I was following this tutorial ... a way to do this ? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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453 views

1 answer

jpa - Testing an EJB with JUnit

How should I test an EJB 3.1 which gets an instance of EntityManager injected? A possible EJB: @Stateless ... provider names had been found. See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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902 views

1 answer

jpa - Hibernate: How specify custom sequence generator class name using annotations?

I want to specify following hbm configuration using annotations: <id name="somePK" column="" ... under @GeneratedValue annotation? See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

0 votes

599 views

1 answer

jpa - Hibernate throws org.hibernate.AnnotationException: No identifier specified for entity: com..domain.idea.MAE_MFEView

Why am I getting this exception? package com.domain.idea; import javax.persistence.CascadeType; import javax.persistence. ... ) ... 145 more See Question&Answers more detail:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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