I have just created and joined 3 new tables. Before creating them everything was working fine so I do believe the root cause is coming from their creation. Now when runned in the browser I receive this error:
org.apache.jasper.JasperException: Exception [EclipseLink-7242]
(Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd):
org.eclipse.persistence.exceptions.ValidationException
Exception Description: An attempt was made to traverse a relationship using indirection that had a null Session. This often
occurs when an entity with an uninstantiated LAZY relationship is
serialized and that lazy relationship is traversed after
serialization. To avoid this issue, instantiate the LAZY relationship
prior to serialization.
How does one instantiate the LAZY relationship prior to serialization anyway? I've been looking all over the web but I still haven't found real working solutions...
I also receive this other error message:
Exception [EclipseLink-4002] (Eclipse Persistence Services -
2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:
Unknown column 't1.rating' in 'field list' Error Code: 1054 Call:
SELECT t1.id, t1.description, t1.last_update, t1.name, t1.price,
t1.rating FROM category_has_product t0, product t1 WHERE
((t0.category_id = ?) AND (t1.id = t0.product_id)) bind => [1
parameter bound] Query: ReadAllQuery(name="productCollection"
referenceClass=Product sql="SELECT t1.id, t1.description,
t1.last_update, t1.name, t1.price, t1.rating FROM category_has_product
t0, product t1 WHERE ((t0.category_id = ?) AND (t1.id =
t0.product_id))")
root cause
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown
column 't1.rating' in 'field list'
What do all those errors mean? I don't understand because all the columns and the rows are perfectly well mapped... It says it canno't find certain columns... I have checked all my tables over and over and I really don't understand what could possibly be wrong... Everything seems fine... A little help would be very much appreciated! Thanks
Besides I use the following for the app:
Netbeans
Glassfish
Mysql
Most pages in jsp
Problem with instantiate lazy reference is well known, so I will provide a link rather than explain myself: http://en.wikibooks.org/wiki/Java_Persistence/Relationships#Serialization.2C_and_Detaching
Wiki page has also 3 solutions to solve the problem. But I will offer you another solution, which may suits your case: JSP usage.
Check https://dzone.com/articles/open-session-view-design (or just google for 'open session in view'. Many pages refers to Hibernate but it applies to Eclipselink also). The solution is start and end transaction in servlet filter. The transaction will cover whole request processing. In your case JSP page generation will be within transaction and lazy references will just work. Benefit is that you don't have to modify your code.
I have no idea about your second problem with mapping
Related
I am trying to map the result of a stored procedure to an entity list and I am guided by the following post https://www.baeldung.com/jpa-sql-resultset-mapping .
Now I am having the next error:
org.hibernate.procedure.UnknownSqlResultSetMappingException: The given
SqlResultSetMapping name [Unknown SqlResultSetMapping [Foo]] is
unknown
I suspect that the problem could be that I am working with several databases in my project.
How could I specify the context or persistence unit in which the resultMapping is?
I am trying to create a data access layer where an application would like to use both a traditional SQL store as well as a NoSQL store. After few searches, I have found a concept like Spring Data MongoDB cross strore and this concept similar to my requirement. So that, I have successfully configured as suggested in the reference document https://stackoverflow.com/a/13998825.
But I am getting below error when I test the above sample. Can some one please help in this regard...
Error: Caused by: org.hibernate.MappingException: Could not determine type for: com.hcc.riab.model.ProductInfo, at table: Product, for columns: [org.hibernate.mapping.Column(productInfo)]
Hi don't understand the problem with namedQuery
<query name="updtae.payment.paymentDate.by.txn_id">
<![CDATA[
update Payment p set p.paymentDate =:payDate WHERE p.txnId=:txnId]]>
</query>
getting exception
HIbernate org.hibernate.HibernateException: Errors in named queries
no columns same us entity Name
It works fine in local And don't on production server
getSession().getNamedQuery("updtae.payment.paymentDate.by.txn_id").setTimestamp("payDate",paymentDate ).setString("txnId", txnId).executeUpdate();
Here is call of named query.
I fix problem buy changing hibernate version
from Hibernate-Version: 3.0.5
to Hibernate-Version: 3.2.1.ga
I have an entity class called User and when I do persistence testing with Arquillian I have always have an error...
Internal Exception: java.sql.SQLSyntaxErrorException: Syntax error: Encountered "USER" at line 1, column 13.
...because of the class name "User". I assume User is the reserved keyword. When I change my entity name to User_ it works fine.
Do I have to change my entity name? Is there anything else I can do to fix this issue?
Yes, USER is a built-in function in Derby. You'd have to specify a different table name for the JPA entity (usually done via the #Table annotation).
I turned off the EclipseLink cache because I'm modifying data externally and don't want the hassle of having to manually refresh everything. Apparently, this is the correct way to switch off the cache in persistence.xml to avoid object identity issues:
<properties>
<property name="eclipselink.cache.shared.default" value="false"/>
</properties>
And here's the exception:
Exception [EclipseLink-6094] (Eclipse Persistence Services - 2.3.0.v20110604-r9504): org.eclipse.persistence.exceptions.QueryException
Exception Description: The parameter name [patient_id] in the query's selection criteria does not match any parameter name defined in the query.
Query: ReadAllQuery(name="file:/C:/dev/repsitory/trunk/java/server/myapp-server/myapp-server-ear/target/gfdeploy/au.com.myapp_myapp-server-ear_ear_1.0-SNAPSHOT/myapp-server-ejb-1.0-SNAPSHOT_jar/_myappPU590288694" referenceClass=PatientRecord sql="SELECT active, new_patient, patient_id_external, rank, patient_id, clinic_system_id FROM postgres.myapp.patient_record WHERE (patient_id = ?)")
I can't even understand the exception message. It's talking about parameter names in the query, but JDBC parameters aren't named.
Any idea how to work around this without switching the cache back on?
As it turns out, I had created an instance of PatientRecord that included one or two detached objects (many-to-one from PatientRecord's perspective). This wasn't a problem with caching on because those objects never became detached.
I merged the objects first then it worked.