java hibernate netbeans xml - java

When i am using net beans to develop one standalone swing application which is transacting with derby database. In my database i dont have any ID field all columns are nullable but when i am mapping my abc.hbm.xml file and validating it is givin following error:-
The content of element type "class" must match "(meta*,subselect?,cache?,synchronize*,comment?,tuplizer*,(id|composite-id),discriminator?,natural-id?,(version|timestamp)?,(property|many-to-one|one-to-one|component|dynamic-component|properties|any|map|set|list|bag|idbag|array|primitive-array),((join,subclass*)|joined-subclass*|union-subclass*),loader?,sql-insert?,sql-update?,sql-delete?,filter*,resultset*,(query|sql-query)*)". [20]
Can anybody help me out with this error.
Cant we map that xml without having ID field in table???

Your XML is invalid, because it doesn't conform to the hibernate DTD. As the error message says, every class element must have either one id sub-element, or one composite-id sub-element.
A hibernate entity must have an ID (simple or composite). Your database schema deosn't seem very clean. You should have a primary key in every table.

Related

Does spring.jpa.hibernate.ddl-auto = validate property validates the columns with table?

In my application i am using below property
spring.jpa.properties.hibernate.hbm2ddl.auto= validate
so does it validates schema like if manually i added one new column in my oracle table and not added this column in java entity .
so in this case will it give error on project startup ?
No, it's perfectly alright to have columns in a table that aren't mapped. An error would be a missing column or table that's mapped to an entity. Your database doesn't need to be identical to your mappings.

Is it possible to have Hibernate ignore the Schema Validation column type mismatch error

I'm updating the db that my application is using. The older schema used short a lot for things like id's etc, but the new schema has updated all these to int.
Using a feature toggle for these mappings is next to near impossible with the code base that I have. And I would like to write the code to be able to use both the legacy db and the new one for testing purposes.
Can I switch off the Schema wrong column type exception in Hibernate and just allow short in the db to be mapped to int in the code?
SchemaManagementException: Schema-validation: wrong column type encountered in
column [AddressTypeID] in table [dbo.AddressType]; found [smallint
(Types#SMALLINT)], but expecting [int (Types#INTEGER)
I think the only solution is to switch to turn off hbm2ddl
hibernate.hbm2ddl.auto=none
With none hibernate skips schema validation

How shall I generate an id for each record in a database table?

I am following https://www.javatpoint.com/crud-in-servlet
to create an CRUD application in servlets and mysql.
Each user inputs his information in a webpage and submit to the web server, which then invokes a servlet SaveServlet to save the information as a record in a database table. The database table however has an additional "id".
SaveServlet.java doesn't create an id for each record. So I was wondering how to create an id for each record?
Thanks.
If you are using jpa/hibernate then your entity must be having the #Id annotation on the record id field (you dont need to set it, it will be done automatically based on you Id generation mechanism defined in the entity class and database schema).
if you are using plain jdbc for persisting records then you need to check the database how primary key is defined. for oracle you can your sequence.nextvalue to set the primary key.

HIBERNATE: Auto append word into TABLE

hi I have an entity with this annotation
#Entity
#Table(name = "REPORT_WORK")
But for some reason hibernate keep saying Missing Table: REPORT_REPORT_WORK
I know that is the problem because of when I change the name to "REPORT_WORKX"
It will say Missing Table: REPORT_REPORT_WORKX
Has any encountered this issue before?
Update: when I change the name to JJJJ
It will say Missing Table: REPORT_JJJJ
so for some reason there it is auto appending REPORT_
Configuration:
hibernate.hbm2ddl.auto=validate
I suspect that the problem is your Hibernate configurations. Specifically, if you don't have an appropriate setting for hibernate.hbm2ddl.auto, Hibernate won't automatically update the database schema when you change your model.
(And if you don't want the updates to happen automatically, then you need to figure out what schema changes are needed, code them as SQL DDL, and run them manually.)
Can you post your persistence.xml (or equivalent)?
It sounds like you are implementing org.hibernate.cfg.NamingStrategy, get rid of this configuration.
Some additional info:
JPA (Hibernate) and custom table prefixes

'Order' entity bean

My database has a table name Order. When I create a new CMP Entity bean, NetBeans 6.9.1 automatically generated a bean with 3 classes name:
Order1.java
Order1Local.java
Order1LocalHome.java
I tried to rename those 3 classes to Order without the 1. I've already edit the ejb-jar.xml file. However, I got this error when deploying the project:
JDO7704: This error (In DatabaseGenerator, failed to get 'relClassName' for 'order') should not occur
I also tried the name OrderBean but it only works with Order1. What should I do to rename my entity bean to Order.
Order is a reserved word in some dbms (used in order by expressions). Maybe that is the reason why Netbeans adds the 1. You should name your table different.
Just found this useful tool: SQL Reserved Words Checker. It says that Order is not reserved in ISO/ANSI,SQL99 but in dbms like DB2 or Oracle.

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