Owned One-to-Many Relationships for GAE not supported by Roo

[jaredrowell]

If I create an owned one-to-many relationship with Google App Engine as the database, using the default Long as the primary key, I get the following error:

Cannot have a java.lang.Long primary key and be a child object

However, I’ve come up with a solution to get owned one-to-many to work using the Key as Encoded String strategy. The first thing I did was set the entity IDs to be a String. Here is my script:

persistence setup --provider DATANUCLEUS --database GOOGLE_APP_ENGINE 
entity --class ~.server.domain.Person --identifierType java.lang.String 
field string --fieldName firstName
field string --fieldName lastName
entity --class ~.server.domain.Address --identifierType java.lang.String 
field string --fieldName streetAddress
field string --fieldName city
field string --fieldName state --permitReservedWords
field string --fieldName zip
field reference --fieldName person --type Person
focus --class Person
field set --fieldName addresses --element Address --cardinality ONE_TO_MANY --mappedBy person
gwt setup

Then I created an aspect to add the extension for encoded string to the entity id and an auto incrementing Long.

package com.test.server.domain;

import org.datanucleus.jpa.annotations.Extension;

privileged aspect Person_Roo_GAE {
	
    declare @field: * Person.id: @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true");

    @Extension(vendorName="datanucleus", key="gae.pk-id", value="true")
    private Long Person.autoId;

    public Long Person.getAutoId() {
        return this.autoId;
    }
    
    public void Person.setAutoId(Long autoId) {
        this.autoId = autoId;
    }
    
}

package com.test.server.domain;

import org.datanucleus.jpa.annotations.Extension;

privileged aspect Address_Roo_GAE {

    declare @field: * Address.id: @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true");

    @Extension(vendorName="datanucleus", key="gae.pk-id", value="true")
    private Long Address.autoId;

    public Long Address.getAutoId() {
        return this.autoId;
    }
    
    public void Address.setAutoId(Long autoId) {
        this.autoId= autoId;
    }

}

And with that minor mod, the scaffold works perfectly with GAE.

[rossjudson]

Putting in this change...thanks for the note!

[boyrud]

If long is not supported in datanucleus as Key, then Key should be default when using datanucleus, I think.

[machaval]

Is there any way to workaround this issue? How do I change the default id generation, so that instead of generating id with Long generates ids with Key, or String?

[James Tyrrell]

This is fixed in master and will be included in the next release of Roo. The related ticket has been closed here.

[cyrille]

James,

It is very unclear for me HOW this problem has been solved in the latest release (1.1.1). Nothing in the JIRA ticket, nor in the different posts of this forum, nor in ANY document gives a clear guidance about how to proceed. The use of com.google.appengine.api.datastore.Key doesn't work.
Could you give any guidance/link about how to REALLY manage owned OneToMany relationships in GAE ?

Thanks in advance.

[martindelemotte]

I tried creating a new project based on jaredrowell's script and using the latest roo from git (1.1.2.BUILD-SNAPSHOT [rev 6c006f1]). It still fails because the primary key of Address is a long.

Like cyrille, I would like to know if there is a way to make one to many owned relationships work on GAE ?

[martindelemotte]

I've dug into it and it seems there is a regression in 1.1.2.BUILD-SNAPSHOT [rev 6c006f1].
I tried with 1.1.1.RELEASE [rev 156ccd6] and I don't get the Long id error.
(but I do get the hardcoded Employee error )

@cyrille : unfortunately, it is said in the JIRA ticket that the chosen solution is to make all relationships unowned.

[dd_angel]

Have the same error with the hardcore "employee" error when i implement a set or a reference field :'(

[Stan Los]

I use 1.1.2.RELEASE.
Have an error: "Cannot have a java.lang.Long primary key and be a child object" for ManyToOne relationship.


entity --class ~.domain.Author --testAutomatically
field string --fieldName name --notNull --sizeMax 25

entity --class ~.domain.Note --testAutomatically
field string --fieldName text --notNull --sizeMax 256
field reference --fieldName author --type ~.domain.Author