Non persisted fields in entity class

Is it possible to declare a field of an entity class such that it does not get persisted?

Yes, use the JPA @Transient annotation (or transient field attribute).
-- James : http://www.eclipselink.org

Similar Messages

  • Need to cache non-persistent field value

    Is it possible to have a non-persistent field in PC class which value will be updated by app, stored in DataCache and then can be used when PC instance will be taken from DataCache next time?
    I tried to map my field as persistence-modifier="transactional" or "none". I do see in my log that the object is taken from cache, but that transient field value is always null after object retreival.
    Thanks, Denis.

    Thanks for the hint, Abe.
    I got what I need via custom filed mapping. If anyone interested:
    public class CacheFieldMapping extends ColumnFieldMapping {
    public CacheFieldMapping(FieldMetaData meta) {
    super(meta);
    public String getMappingType() {
    return getClass().getName();
    protected int getJDBCType() {
    return Types.OTHER;
    public boolean map() {
    return true;
    public void fromMappingInfo(MappingInfo info, boolean adapt) {
    // do nothing...
    public void toMappingInfo(MappingInfo info) {
    // do nothing...
    public void refSchemaComponents() {
    // do nothing...
    public int select(Select sel, KodoStateManager sm, JDBCStoreManager store,
    JDBCFetchConfiguration fetch, int eagerMode) {
    return -1;
    public void load(KodoStateManager sm, JDBCStoreManager store,
    JDBCFetchConfiguration fetch, Result res) throws SQLException {
    // do nothing...
    public void load(KodoStateManager sm, JDBCStoreManager store,
    JDBCFetchConfiguration fetch) throws SQLException {
    sm.storeObject(getIndex(), null);
    public Object loadProjection(JDBCStoreManager store,
    JDBCFetchConfiguration fetch, Result res, Joins joins) throws SQLException
    return null;
    public Boolean isCustomInsert(KodoStateManager sm) {
    return Boolean.TRUE;
    public Boolean isCustomUpdate(KodoStateManager sm) {
    return Boolean.TRUE;
    protected void update(KodoStateManager sm, Row row) throws SQLException {
    // do nothing...
    "Abe White" <[email protected]> wrote in message
    news:[email protected]..
    No, this is not possible. The data cache acts exactly like the
    database, only storing persistent values.

  • Updating non-persistent fields in an Entity Object

    Hi,
    I wanted to add a non-persistent field to an Entity Object to use as a temporary aggregate field for a detail entity. It appears that storing data in the field makes it look like the master entity has been updated even though the value cannot be saved in the data base. Is this the way it is supposed to work?
    I was trying to avoid putting invisible controls in the UI or creating "global" variables.
    Thanks,
    Peter

    This can be done with programmatic VOs: http://download.oracle.com/docs/cd/E15523_01/web.1111/b31974/bcadvvo.htm#sm0341
    Sample: http://blogs.oracle.com/smuenchadf/examples/#132
    You can also opt to do this with a simple Java class and a data control based on it.
    For example: http://blogs.oracle.com/shay/2009/07/java_class_data_control_and_ad.html

  • Non-persistent fields

    Hi,
    I would like to use toplink with objects that contains both persistent and non-persistent fields (unmapped). When I insert such an object to the database using unit-of-work, and then try to query toplink for that same object elsewhere in my program I only get the persistent fields. I've tried using checkCacheThanDatabase() which resolved the problem but this method is only available for ReadObjectQuery not for ReadAllQuery (the javadoc is not consistent with the code).
    My questions:
    1. For ReadObjectQuery, can I trust the cache to always have my object, or is there a risk that the cache will drop it?
    2. What to do with ReadAllQuery?
    3. Any other approach that can work?

    You can make non-persistent attributes remain with the object in a unit of work through using a clone policy and using the postMerge event.
    Your class needs to implement Cloneable and in the descriptor use clone-copy-policy. This will ensure that when a cached object is registered into the unit of work the non-persistent attributes will be maintained.
    When the unit of work merges a transactional object into the session cache you need to make sure you copy the non-persistent attributes from the clone to the cached object. You can do this through a DescriptorEventListener and the postMerge event.
    Example:
    postMerge(DescriptorEvent event) {
    String tempProperty = ((MyClass) event.getObject()).getProperty();
    ((MyClass) event.getOringalObject()).setProperty(tempProperty);
    Note that since the attribute is non-persistent it will not be guaranteed to persist indefinitely. The non-persistent attributes duration will be dependant on your caching policy, if it gets dropped from the cache, a new instance will be built from the database the next time it is accessed.
    The checkCacheThanDatabase checkCacheOnly properties should not have any effect on what you get from the cache. Reads that access the database will still maintain object identity with the cache, and you should get back the correct object.

  • Non-persistent field

    Hi,
    We have a need for a kodo-enhanced object to have a member field that
    should NOT be persisted in the database.
    I searched the docs several times but could not find the metadata to
    specify this option. Any help would be greatly appreciated.
    John

    We have a need for a kodo-enhanced object to have a member field that
    should NOT be persisted in the database.<field name="foo" persistence-modifier="none"/>
    or make the field transient and it won't be persistent by default.

  • Field that is not persistent in Entity class

    Hi all,
    I have entity class "Author" it has OneToMany relationship with "Article" Entity.
    I want to create nbArticles in Author class, just is Long variable to get number of Articles created by this Author. That field is not persist just calculated from query, how can i define new field in Entity class without JPA manages persistance over it? Thanks.
    PD: sorry for my English, im from South America
    Best regards,

    Thanks a lot.
    Best regards,

  • Marking a field as non-persistent?

    Hi folks,
    We've been building up a distributed data store that has a BDB at each leaf node. There are a few layers that our objects go through, and up until now we've been able to use our Entity objects directly throughout the code. They get serialized by RMI and make their way to our BDB nodes and get persisted by the DPL.
    But now we have a situation where we have a field that we want serialized (non-transient) so that it makes its way all the way through our system, but then not persistent when it reaches the DPL. (We also have a search index at each leaf, and this bit of data includes some instructions for the search engine.)
    The best solution (from my perspective!) would be simply to have an @NonPersistent annotation to make the DPL ignore a particular field. Lacking that, I came up with a couple options, neither of which I like. First, I could add a wrapper object that isn't an Entity class that contains my non-persistent data. I don't really like this idea, but it could work (makes all my objects a little larger and they get serialized a LOT). Second, I could modify readObject and writeObject to manually throw in the transient fields that I wanted to keep around. I don't really like that either (for different reasons), but it also could work.
    Any other thoughts? Is there anything I'm missing that would allow me to do this easily?
    Thanks!
    Jeff

    Hi Jeff,
    I think the addition of @NonPersistent is a reasonable request and probably the only good solution. One of the primary goals of the DPL is to be able to persist objects that are used in other ways -- RMI is a good example. In other words, the DPL intends to be a pure POJO persistence solution. However, we didn't consider the case of a field that is persistent with respect to RMI but not the DPL, or vice-versa. So I think solving this is important.
    Let us spend some time on that and we'll see if we can get this into a 3.3 dot release. This is a fairly simply addition, but we'll need to also consider the reverse situation -- a field that is persistent WRT the DPL but not RMI. In other words, we may need both @Persistent and @NonPersistent to apply to a field to override the default rules. And we'll need to encapsulate this information in the EntityModel abstraction so that it can be used without annotations.
    In the meantime, I suggest using one of the workarounds you mentioned, or perhaps even modifying the DPL source code in a way that works for you, temporarily.. If you choose the latter, note that there is only one place where field persistence is determined, which is in the getInstanceFields method of this class:
    src/com/sleepycat/persist/impl/FieldInfo.java
    See the call to Modifier.isTransient.
    --mark                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

  • Weird exception: Cannot instantiate non-persistent class: java.util.Map

    java.lang.UnsupportedOperationException: Cannot instantiate non-persistent class: java.util.Map
         at com.sleepycat.persist.impl.NonPersistentFormat.newInstance(NonPersistentFormat.java:45)
         at com.sleepycat.persist.impl.PersistEntityBinding.readEntity(PersistEntityBinding.java:89)
         at com.sleepycat.persist.impl.PersistEntityBinding.entryToObject(PersistEntityBinding.java:61)
         at com.sleepycat.persist.PrimaryIndex.put(PrimaryIndex.java:338)
         at com.sleepycat.persist.PrimaryIndex.put(PrimaryIndex.java:299)
         at com.xx.support.dbd.IdentityDataAccessor.insert(IdentityDataAccessor.java:33)
         at com.xx.support.dbd.BerkeleyDBAccountStorage.saveUser(BerkeleyDBAccountStorage.java:95)
         at com.xx.support.bdb.BerkeleyDBAccountStorageTests.initBerkeleyDBData(BerkeleyDBAccountStorageTests.java:38)
         at com.xx.support.bdb.BerkeleyDBAccountStorageTests.setUp(BerkeleyDBAccountStorageTests.java:28)
         at junit.framework.TestCase.runBare(TestCase.java:125)
         at junit.framework.TestResult$1.protect(TestResult.java:106)
         at junit.framework.TestResult.runProtected(TestResult.java:124)
         at junit.framework.TestResult.run(TestResult.java:109)
         at junit.framework.TestCase.run(TestCase.java:118)
         at junit.framework.TestSuite.runTest(TestSuite.java:208)
         at junit.framework.TestSuite.run(TestSuite.java:203)
    What's the root cause of this exception?

    I wrote a small test using the classes you included
    in your message and I am able to retrieve the user by
    key, as in the code above. So I'm not sure what
    you're doing that is causing the problem. Please
    send a small test that reproduces the problem.Oops, I forgot to include the source for the test I wrote. Here it is.
    import java.io.File;
    import java.util.HashMap;
    import java.util.Map;
    import com.sleepycat.je.DatabaseException;
    import com.sleepycat.je.Environment;
    import com.sleepycat.je.EnvironmentConfig;
    import com.sleepycat.persist.EntityStore;
    import com.sleepycat.persist.PrimaryIndex;
    import com.sleepycat.persist.StoreConfig;
    import com.sleepycat.persist.model.Entity;
    import com.sleepycat.persist.model.Persistent;
    import com.sleepycat.persist.model.PrimaryKey;
    public class Test {
        @Persistent
        public static class SimplePrincipal {
            protected String name;
            public SimplePrincipal(String username) {
                this.name = name;
            public SimplePrincipal() {}
        @Entity
        public static class SimpleUser extends SimplePrincipal {
            @PrimaryKey
            private String key;
            private Map properties;
            public SimpleUser() {
                super();
                this.properties = new HashMap();
            public SimpleUser(String username) {
                super(username);
                this.properties = new HashMap();
            public void setKey(String key){
                this.key = key;
            public void addPropertity(String name, String value) {
                this.properties.put(name, value);
            @Override
            public String toString() {
                return "[SimpleUser key: " + key + " name: " + name + ']';
        private Environment env;
        private EntityStore store;
        private PrimaryIndex<String, SimpleUser> primaryIndex;
        private void open()
            throws DatabaseException {
            EnvironmentConfig envConfig = new EnvironmentConfig();
            envConfig.setAllowCreate(true);
            envConfig.setTransactional(true);
            env = new Environment(new File("./data"), envConfig);
            StoreConfig storeConfig = new StoreConfig();
            storeConfig.setAllowCreate(true);
            storeConfig.setTransactional(true);
            store = new EntityStore(env, "test", storeConfig);
            primaryIndex = store.getPrimaryIndex(String.class, SimpleUser.class);
        private void close()
            throws DatabaseException {
            store.close();
            env.close();
        private void execute()
            throws DatabaseException {
            SimpleUser user = new SimpleUser("test");
            user.setKey("testkey");
            primaryIndex.put(user);
            user = primaryIndex.get("testkey");
            System.out.println(user);
        public static void main(String[] args)
            throws DatabaseException {
            Test test = new Test();
            test.open();
            test.execute();
            test.close();
    }Mark

  • Entity beans caching non-persistent data between transactions

    Some of the properties in our entity bean implementation classes are not declared
    in our descriptor files, and therefore, are non-persistent (we are using container-managed
    persistence); I will refer to these properties as "non-persistent properties".
    In WebLogic 5.1, we've noticed that the non-persistent properties are cached in
    between transactions. For instance, I ask for a particular Person (Person(James)),
    and I set one of the non-persistent properties (Property(X)) inside Transaction(A).
    In Transaction(B) (which is exclusive of Transaction(A)), I access Property(X)
    and find that it is the same value as I had set in Transaction(A)- this gives
    the appearance that non-persistent entity properties are being cached in between
    transactions.
    The same appears to hold true in WebLogic 7 SP1, however, we must use the "Exclusive"
    concurrency-strategy to maintain this consistency.
    I am worried that this assumption we are making of non-persistent properties is
    not valid in all cases, and the documentation does not promise anything in the
    way of such an assumption. I am worried that the container could kill the Person(James)
    entity implementation instance in the pool after Transaction(A), and create a
    new Person(James) instance to serve Transaction(B)- once that happens our assumption
    fails.
    "Database" concurrency strategy seems to fail our assumption on a regular basis,
    but that makes sense, since the documentation states that the "database will maintain
    the cache", and the container seems more willing to kill instances when they are
    finished with, or create new instances for new transactions.
    So my question is this: What is exactly guaranteed by the "Exclusive" concurrency-strategy?
    Will the assumption that we've made above ever fail under this strategy?
    Thanks in advance for any help.
    Regards,
    James

    It simply means that there is only one entity bean instance per PK in the
    server, and transaction which uses it locks it exclusively.
    James DeFelice <[email protected]> wrote:
    Thank you for the suggestion. I have considered taking this path, but before I
    make a final decision, I was hoping to get a clear answer to the question that
    I stated below:
    What EXACTLY is guaranteed by the "Exclusive" concurrency-strategy? Maybe someone
    from BEA knows?
    "Cameron Purdy" <[email protected]> wrote:
    To be safe: You should clear those values before the ejb load or set
    them
    after (or both).
    Peace,
    Cameron Purdy
    Tangosol, Inc.
    http://www.tangosol.com/coherence.jsp
    Tangosol Coherence: Clustered Replicated Cache for Weblogic
    "James DeFelice" <[email protected]> wrote in message
    news:[email protected]...
    Some of the properties in our entity bean implementation classes arenot
    declared
    in our descriptor files, and therefore, are non-persistent (we areusing
    container-managed
    persistence); I will refer to these properties as "non-persistentproperties".
    In WebLogic 5.1, we've noticed that the non-persistent properties arecached in
    between transactions. For instance, I ask for a particular Person(Person(James)),
    and I set one of the non-persistent properties (Property(X)) insideTransaction(A).
    In Transaction(B) (which is exclusive of Transaction(A)), I accessProperty(X)
    and find that it is the same value as I had set in Transaction(A)-this
    gives
    the appearance that non-persistent entity properties are being cachedin
    between
    transactions.
    The same appears to hold true in WebLogic 7 SP1, however, we must usethe
    "Exclusive"
    concurrency-strategy to maintain this consistency.
    I am worried that this assumption we are making of non-persistentproperties is
    not valid in all cases, and the documentation does not promise anythingin
    the
    way of such an assumption. I am worried that the container could killthe
    Person(James)
    entity implementation instance in the pool after Transaction(A), andcreate a
    new Person(James) instance to serve Transaction(B)- once that happensour
    assumption
    fails.
    "Database" concurrency strategy seems to fail our assumption on a regularbasis,
    but that makes sense, since the documentation states that the "databasewill maintain
    the cache", and the container seems more willing to kill instanceswhen
    they are
    finished with, or create new instances for new transactions.
    So my question is this: What is exactly guaranteed by the "Exclusive"concurrency-strategy?
    Will the assumption that we've made above ever fail under this strategy?
    Thanks in advance for any help.
    Regards,
    James
    Dimitri

  • Accessing entity class field values in a visual JSF page

    There is a convenient way to access a session values into a JSF visual page using the following:
    String mySessionValue = (String) getValue("#{sessionScope.name}");Like the same, are there any ways to access entity class field values into a visual JSF page? Are there any concepts similar to "entityClassDataProvider" that can be linked to a table component in a visual JSF page?
    Thank you.

    My question is about (Netbeans visual pack) Java Persistence API and how to display the information from an entity class to a JSF page. But the above mentioned tutorial is about the ordinary visual table presentation.
    Thank you.

  • Update non-editable field Start date which is calculated from other context

    I had created some custom date fields(model, bol entity) in component ICCMP_BTSHEAD. We are calculating Start date based on the new input value into receiving date in the other context node.
    so, for this i get the value on controller class(_IMPL). and pass the same value in the GET method of Start date.
    But, Problem is Start date is the non-editable field so SET method will not be trigger as expected. so the same i used the DO_PREPARE_OUTPUT method but it's called and update the value when we press the enter. IF directly we click on the "SAVE" button then it' trigger but value is not updating in the database.
    Please, find the below piece of code for the same. can u please anybody help me that how can i achieve this requirement.
    DATA: l_recieve_date     TYPE crmt_date_timestamp_from,
            lr_current TYPE REF TO cl_bsp_wd_mixed_node,
            lr_col      TYPE REF TO cl_bsp_wd_collection_wrapper.
      DATA: lv_date TYPE d,
             lv_time TYPE t,
             lv_date_temp TYPE sydatum.
      IF iv_first_time EQ abap_false. "avoid for first tile load
    Read the value of btreceivedate-TIMESTAMP_FROM.
        lr_col = me->ztyped_context->btreceivedate->get_collection_wrapper( ).
        IF lr_col IS BOUND.
          lr_current ?= lr_col->get_current( ).
          IF lr_current IS BOUND.
            lr_current->if_bol_bo_property_access~get_property_as_value( EXPORTING iv_attr_name = 'TIMESTAMP_FROM'
                                       IMPORTING ev_result   = l_recieve_date ).
          ENDIF.
        ENDIF.
        IF l_recieve_date IS NOT INITIAL.
          CONVERT TIME STAMP l_recieve_date TIME ZONE sy-zonlo
                    INTO DATE lv_date TIME lv_time.
    Check day is working day - if not, correct to previous working day
          IF lv_date IS NOT INITIAL.
            lv_date_temp = lv_date.
            CALL FUNCTION 'DATE_CONVERT_TO_FACTORYDATE'
              EXPORTING
                correct_option      = '-'
                date                = lv_date
                factory_calendar_id = 'GB'
              IMPORTING
                date                = lv_date_temp
              EXCEPTIONS
                date_after_range    = 1
                date_before_range   = 2.
            IF sy-subrc IS INITIAL.
              lv_date = lv_date_temp.
            ENDIF.
          ENDIF.
          CONVERT DATE lv_date TIME lv_time
                 INTO TIME STAMP l_recieve_date TIME ZONE sy-zonlo.
        ENDIF.
        lr_col = me->ztyped_context->btstart->get_collection_wrapper( ).
        IF lr_col IS BOUND.
          lr_current ?= lr_col->get_current( ).
          IF lr_current IS BOUND.
            lr_current->if_bol_bo_property_access~set_property(
                       iv_attr_name = 'APPT_TYPE'               "#EC NOTEXT
                       iv_value     = 'ZSTWTIME0001' ).
            lr_current->if_bol_bo_property_access~set_property(
                            iv_attr_name = 'TIMESTAMP_FROM'     "#EC NOTEXT
                            iv_value     = l_recieve_date ).
          ENDIF.
        ENDIF.
      ENDIF.
    could you please help me?

    Hi,
    Thanks for your reply,
    yes, i checked the same thing also. But DO_HANDLE_DATA is called before the SET method of receiving date and in that case we are getting the old value in DO_HANDLE _DATA and  source and Target fields both are not updating.
    I checked, if, i'll change the input field then set method of input field and then EH_ON_SAVE is called directly.
    i think, if i'll do the same modification in the EH_ON_SAVE method as i did in the DO_PREPARE_OUTPUT then it can be updated but i don't want to change the EH_ON_SAVE at this moment.
    is there any other way to update the START DATE(Display mode in the screen) which is calculate from the other context node field receiving date.

  • How to annotate non-persistence fields?

    Hi,
    I am using TopLink Essentials as my JPA provider. I have few objects where I don't have a mapping of fields on the object to the database columns. Basically I would like to use few fields in the object to create some behaviour and doesn't want to persist or query. By default, TopLink is reading all the fields and mapping them to the table I defined and I am getting the "Invalid Identifier" errors. Is there a way I can tell TopLink to ignore certain fields in an Entity class for the persistence. I have used the @Column annotation for all my fields that are in the DB to map. Can I use any annotations for this purpose or any other ways to achieve this? I do not want create separate subclasses just for 2 or 3 fields that I use. Your help is appreciated.

    I just found out that I can use @Transient. Problem solved.

  • Single Persistent instance of a Object, Many non persistant. Same Identity on persist

    I have a persistent bean class with two Strings as member fields. (example
    below)
    I have many other classes that use it a part of they're member fields.
    I need to have only one persistant version of it (One row, to many Rows in
    different tables). But can have many non persistant versions. I can't
    control the creation of the non persistant objects.
    i.e.
    On persist, How can I configuration JDO to detect that it's the same as an
    object already in the database and use that instead?
    example:
    // Example class One
    package foo;
    public class One(){
    public String var1;
    public String var2;
    public String getVar1(){
    return this.var1;
    public void setVar1(String var1Set){
    this.var1 = var1Set
    public String getVar2(){
    return this.var2;
    public void setVar2(String var2Set){
    this.var2 = var2Set
    /// one.jdo
    <?xml version="1.0"?>
    <jdo>
    <package name="foo">
    <class name="One"/>
    </package>
    </jdo>
    ///Example Scenario
    One oneObject = new One();
    oneObject.setVar1("Value1");
    oneObject.setVar2("Value2");
    pm.makePersistent(oneObject); // one row in database
    /// Some time later, in a different thread, or since JVM shutdown and
    restart
    One oneObject = new One();
    oneObject.setVar1("Value1");
    oneObject.setVar2("Value2");
    pm.makePersistent(oneObject); // one row in database, instead of two.

    You cannot. You should either find the object by query or retrieve it
    using application identity.
    Graham Cruickshanks wrote:
    I have a persistent bean class with two Strings as member fields. (example
    below)
    I have many other classes that use it a part of they're member fields.
    I need to have only one persistant version of it (One row, to many Rows in
    different tables). But can have many non persistant versions. I can't
    control the creation of the non persistant objects.
    i.e.
    On persist, How can I configuration JDO to detect that it's the same as an
    object already in the database and use that instead?
    example:
    // Example class One
    package foo;
    public class One(){
    public String var1;
    public String var2;
    public String getVar1(){
    return this.var1;
    public void setVar1(String var1Set){
    this.var1 = var1Set
    public String getVar2(){
    return this.var2;
    public void setVar2(String var2Set){
    this.var2 = var2Set
    /// one.jdo
    <?xml version="1.0"?>
    <jdo>
    <package name="foo">
    <class name="One"/>
    </package>
    </jdo>
    ///Example Scenario
    One oneObject = new One();
    oneObject.setVar1("Value1");
    oneObject.setVar2("Value2");
    pm.makePersistent(oneObject); // one row in database
    /// Some time later, in a different thread, or since JVM shutdown and
    restart
    One oneObject = new One();
    oneObject.setVar1("Value1");
    oneObject.setVar2("Value2");
    pm.makePersistent(oneObject); // one row in database, instead of two.
    Steve Kim
    [email protected]
    SolarMetric Inc.
    http://www.solarmetric.com

  • Problem creating non-persistent Child Objects

    I have the need to create a non persistable child object in the
    jdoPreStore of a parent object. I then perform some tests on the parent
    to determine if the child object needs to be persisted or not. If I leave
    the child non persistent it still writes to the database.
    I was performing the follwoing piece of code
    Class Parent {
    // The relationship is a 0 to many
    public Child createChild() {
    Child child = .....//create non persistent object
    child.setParent(this);
    getChild().add(child);
    It appears that if I remove the getChild().add(child). It does not
    persist (as desired).
    Is this correct behaviour?? I dont think that it should be, but if it is
    then I have a further problem.
    If that child object inherits from another object and you remove the
    getChild().add(child) kodo outputs an invalid object to the database. It
    doesnt insert a row to the child table. But it inserts a row to the
    childs inherited object table. This is now an invalid object and will
    fail upon loading.
    Any help on this would be appreciated.
    Thanks
    Luke.

    JDO has something called persistence by reachability. This means that
    objects do not have to explicitly be marked as to be persistent as JDO
    will traverse the object graph to ensure that all nodes are persistent.
    I think you are seeing this behavior combined with another side
    behavior: Kodo requires that both sides of a relation be set.
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    Luke.
    Steve Kim
    [email protected]
    SolarMetric Inc.
    http://www.solarmetric.com

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