Hi Michael,
Thank you for helping. Yes… you modeled exactly what I described down to the
delete rules. I imported your files in modeler and run class generation but I
still get the relationship (TO_SHIP in your model) to appear as mandatory.
Could it be an issue in class generation?
This is a little VE snippet I use in my template to output a static list of
mandatory relationships.
#foreach( $rel in ${object.DeclaredRelationships} )
#if (${rel.isMandatory()} && !${rel.ToMany} )
#set($bar =
$requiredRelationships.add("${stringUtils.capitalizedAsConstant($rel.Name)}_PROPERTY"))
#end
#end
public static final List<String> REQUIRED_RELATIONSHIPS = List.of(
#foreach( $rel in ${requiredRelationships} )
${rel}#if(!$foreach.last),#end
#end
);
And contrary to what I would expect, I get this in my superclass:
public static final List<String> REQUIRED_RELATIONSHIPS = List.of(
TO_SHIP_PROPERTY
);
Riccardo De Menna
> On 10 Jan 2024, at 01:20, Michael Gentry <[email protected]> wrote:
>
> Hi Riccardo,
>
> I may have completely misunderstood your intention, but here is my first
> cut for a model:
>
> cayenne-o2o.xml:
> <?xml version="1.0" encoding="utf-8"?>
> <domain xmlns="http://cayenne.apache.org/schema/10/domain";
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
> xsi:schemaLocation="http://cayenne.apache.org/schema/10/domain
> https://cayenne.apache.org/schema/10/domain.xsd";
> project-version="10">
> <map name="datamap"/>
> </domain>
>
> datamap.map.xml:
> <?xml version="1.0" encoding="utf-8"?>
> <data-map xmlns="http://cayenne.apache.org/schema/10/modelMap";
> xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
> xsi:schemaLocation="http://cayenne.apache.org/schema/10/modelMap
> https://cayenne.apache.org/schema/10/modelMap.xsd";
> project-version="10">
> <property name="defaultLockType" value="1"/>
> <property name="defaultPackage" value="org.test"/>
> <db-entity name="SHIPMENT">
> <db-attribute name="ID" type="BIGINT" isPrimaryKey="true" isMandatory="true"
> />
> </db-entity>
> <db-entity name="SHIPMENT_NUMBER">
> <db-attribute name="ID" type="BIGINT" isPrimaryKey="true" isMandatory="true"
>>
> <info:property xmlns:info="http://cayenne.apache.org/schema/10/info"; name=
> "comment" value="This ID is the same as SHIPMENT's ID."/>
> </db-attribute>
> <db-attribute name="NUM" type="INTEGER">
> <info:property xmlns:info="http://cayenne.apache.org/schema/10/info"; name=
> "comment" value="This is the shipment number."/>
> </db-attribute>
> </db-entity>
> <obj-entity name="Shipment" className="org.test.Shipment" lock-type=
> "optimistic" dbEntityName="SHIPMENT"/>
> <obj-entity name="ShipmentNumber" className="org.test.ShipmentNumber"
> lock-type="optimistic" dbEntityName="SHIPMENT_NUMBER">
> <obj-attribute name="num" type="java.lang.Integer" db-attribute-path="NUM"/>
> </obj-entity>
> <db-relationship name="toShipNum" source="SHIPMENT" target="SHIPMENT_NUMBER"
>>
> <db-attribute-pair source="ID" target="ID"/>
> </db-relationship>
> <db-relationship name="toShip" source="SHIPMENT_NUMBER" target="SHIPMENT"
> toDependentPK="true">
> <db-attribute-pair source="ID" target="ID"/>
> </db-relationship>
> <obj-relationship name="toShipNum" source="Shipment" target="ShipmentNumber"
> deleteRule="Cascade" db-relationship-path="toShipNum"/>
> <obj-relationship name="toShip" source="ShipmentNumber" target="Shipment"
> deleteRule="Deny" db-relationship-path="toShip"/>
> </data-map>
>
> Copy/Paste these files somewhere, then try loading them up into your 4.2
> Modeler and see if it is close.
>
> mrg
>
>
> On Tue, Jan 9, 2024 at 9:54 AM Riccardo De Menna <[email protected]> wrote:
>
>> Hi,
>>
>> Can someone help me understand something?
>>
>> I’m trying to model a one-to-one relationship between two entities but I
>> can’t seem to get the relationship to be optional.
>>
>> In my specific case I need to model an entity representing shipments with
>> a postal service. Each shipment needs to have a number taken from a
>> range/group that is pre-assigned by the postal service.
>>
>> Thus I created a SHIPMENT_NUMBER entity with just an INTEGER attribute and
>> then used that attribute to build the relationship with the SHIPMENT
>> entity. Possibly with “To dep PK” as well.
>>
>> I want the relationship to be optional so that I can generate
>> SHIPMENT_NUMBER as many as I want and populate them with the numbers
>> assigned by the postal service and only later, when the real SHIPMENT is
>> actually needed/created, link it with the number in a one-to-one fashion.
>>
>> I’m not sure why, but my class generated content always shows the
>> relationship as mandatory.
>>
>> Coming from the WebObjects world, I'm used to a modeler that explicitly
>> shows checkboxes for isMandatory on relationships like with the attributes.
>> Here in Cayenne it seems that optionality is implicitly determined based on
>> the design.
>>
>> Have I misunderstood something? Is my design flawed?
>>
>> Any tip is appreciated.
>>
>> Regards,
>> Riccardo
