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Foreign Key Constraint Issue Involving One-To-Many and Many-To-One Relationship in EcliplseLink2.1. [message #656552]

Sat, 26 February 2011 17:47

No real name

Messages: 6
Registered: February 2011

Junior Member

Hi all,

I'm encountering a 1452 error on MySQL 5.5.9 while running some JPA tutorial code that I pulled off the EclipseLink website ( http://wiki.eclipse.org/EclipseLink/Examples/JPA/EmployeeXML), and I'm hoping someone has some insight.

I'm using the latest stable build for EclipseLink as of today from the main website: eclipselink-jpa-modelgen_2.1.2.v20101206-r8635.jar and javax.persistence_2.0.1.v201006031150.jar.

When I populate the database via CreateDatabase.java, I get the following error:

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViol ationException: Cannot add or update a child row: a foreign key constraint fails (jpatutorial.proj_emp, CONSTRAINT FK_PROJ_EMP_PROJ_ID FOREIGN KEY (PROJ_ID) REFERENCES PROJECT (PROJ_ID)) Error Code: 1452

The relevant models here are an Employee table and a Phone table. There is many-to-one relationship between Phones and Employees. Part of the orm.xml is below:

<entity class="model.PhoneNumber">
<table name="PHONE" />
<attributes>
.
.
<many-to-one name="owner">
<join-column name="EMP_PH_ID" />
</many-to-one>
</attributes>
</entity>

<entity class="model.Employee">

<attributes>
<id name="id">
<column name="EMP_ID" />
<generated-value />
</id>
.
.
<one-to-many name="phoneNumbers" mapped-by="owner">
<cascade>
<cascade-all />
</cascade>
<private-owned />
</one-to-many>
.
.
</attributes>
</entity>

The code successfully creates the tables, creates address records for the employees, creates all the employee records, but then fails on inserting a phone record even though it has a valid FK reference to a employee record. I simplified the code so that it executes, persists and commits everything up to the point of the failure, but whether I execute the insert through JPA or manually by running a SQL script, I end up with the same 1452 error.

Interestingly, I found that if I dropped all the related Employee entities, and recreate them off create table definitions reversed engineered by MySQL workbench, I am able to successfully insert records into all the tables through JPA and manually via scripts. So, this suggests Eclipselink is creating the tables in some way that is producing a problem, and MySQL Workbench isn't capturing these problematic definitions in the reverse engineering. At this point, I'm out of ideas.

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