user aliases for more then one attribute path segment

[Kohlweiss Georg <Ge...@oekb.at>]

Hi!

First of all I want to mention that OJB does a lot of work for me and is a great project!

Many problems i had with user aliases i solved for my own, but now i can't find a way out :(

Here's my problem:

I have 2 Object-Classes
ItemImpl and PropertyImpl (one item has many named properties, ItemImpl 1--M PropertyImpl)


Here is my classdescr:

<class-descriptor
        class="ItemImpl"
        table="ITEMS"
    >



        <field-descriptor id="1"
            name="id"
            column="ID"
            jdbc-type="BIGINT"
            nullable="false"
            primarykey="true"
            autoincrement="true"
            sequence-name="IT_SEQ"
            />

        <collection-descriptor
            name="allProperties"
            element-class-ref="PropertyImpl"
            orderby="id"
            sort="ASC"
            proxy="true"
        >
            <inverse-foreignkey field-id-ref="4"/>
        </collection-descriptor>
        
		<collection-descriptor
            name="allDetailItemProperties"
            element-class-ref="PropertyImpl"
            orderby="id"
            sort="ASC"
            proxy="true"
        >
            <inverse-foreignkey field-id-ref="5"/>
        </collection-descriptor>


    </class-descriptor>


    <class-descriptor
        class="PropertyImpl"
        table="PROPERTIES"
    >

        <field-descriptor id="1"
            name="id"
            column="ID"
            jdbc-type="BIGINT"
            nullable="false"
            primarykey="true"
            autoincrement="true"
            sequence-name="P_SEQ"
            />
        <field-descriptor id="4"
            name="itemId"
            column="IT_ID"
            jdbc-type="BIGINT"
            nullable="false"
            />
        <field-descriptor id="5"
            name="itemIdReferenced"
            column="IT_ID_REF"
            jdbc-type="BIGINT"
            nullable="false"
            />
                <field-descriptor id="6"
                    name="name"
                    column="NAME"
                    jdbc-type="VARCHAR"
                    nullable="false"
                    length="4000"
                    />
                <field-descriptor id="7"
                    name="value"
                    column="VALUE"
                    jdbc-type="VARCHAR"
                    nullable="false"
                    length="4000"
                    />

        <reference-descriptor name="item"
                              class-ref="ItemImpl"
                              proxy="true">
            <foreignkey field-id-ref="4"/>
        </reference-descriptor>

        <reference-descriptor name="itemReferenced"
                              class-ref="ItemImpl"
                              proxy="true">
            <foreignkey field-id-ref="5"/>
        </reference-descriptor>

    </class-descriptor>



Of course PropertyImpl has one reference to its corresponding ItemImpl object, but PropertyImpl has another reference to ItemImpl because
a property of an item can point to another parent item, e.g. a persons property named myHome points to a separate home item.

Now I want to query all home items (maybe distinct), which where referenced from a person item matching some property-criterias.
I defined a Criteria-Tree like this:

#############################

Criteria rootCrit = new Criteria();

rootCrit.addEqualTo("allDetailItemProperties.name", "myHome");

Criteria propCrit1 = new Criteria();

propCrit1.setAlias("prop1", "allProperties");
propCrit1.addEqualTo("allDetailItemProperties.item.allProperties.name",  "firstName");
propCrit1.addEqualTo("allDetailItemProperties.item.allProperties.value", "Jack");

rootCrit.addAndCriteria(propCrit1);

Criteria propCrit2 = new Criteria();

propCrit2.setAlias("prop2", "allProperties");
propCrit2.addEqualTo("allDetailItemProperties.item.allProperties.name",  "hairColor");
propCrit2.addEqualTo("allDetailItemProperties.item.allProperties.value", "black");

rootCrit.addAndCriteria(propCrit2);

Collection result = PersistenceBrokerFactory.defaultPersistenceBroker ().
	getCollectionByQuery(new QueryByCriteria(ItemImpl.class, rootCrit));

#############################

This works fine, but if the selected homes have to satisfy another criteria of a detail item,
e.g. all homes that have a red chrysler car in their garage, additional aliases in the path segment "allDetailItemProperties"
have to be used.
I didn't got it working, i tried it that way:

#############################

Criteria rootCrit = new Criteria();

rootCrit.setAlias("detail1", "allDetailItemProperties");
rootCrit.addEqualTo("allDetailItemProperties.name", "myHome");

Criteria propCrit1 = new Criteria();

propCrit1.setAlias("prop1", "allProperties");
propCrit1.addEqualTo("allDetailItemProperties.item.allProperties.name",  "firstName");
propCrit1.addEqualTo("allDetailItemProperties.item.allProperties.value", "Jack");

rootCrit.addAndCriteria(propCrit1);

Criteria propCrit2 = new Criteria();

propCrit2.setAlias("prop2", "allProperties");
propCrit2.addEqualTo("allDetailItemProperties.item.allProperties.name",  "hairColor");
propCrit2.addEqualTo("allDetailItemProperties.item.allProperties.value", "black");

rootCrit.addAndCriteria(propCrit2);


Criteria rootCrit2 = new Criteria();

root2Crit.setAlias("detail2", "allDetailItemProperties");
root2Crit.addEqualTo("allDetailItemProperties.name", "carsHome");

Criteria propCrit3 = new Criteria();

propCrit3.setAlias("prop3", "allProperties");
propCrit3.addEqualTo("allDetailItemProperties.item.allProperties.name",  "manufactory");
propCrit3.addEqualTo("allDetailItemProperties.item.allProperties.value", "chrysler");

rootCrit2.addAndCriteria(propCrit3);

Criteria propCrit4 = new Criteria();

propCrit4.setAlias("prop4", "allProperties");
propCrit4.addEqualTo("allDetailItemProperties.item.allProperties.name",  "color");
propCrit4.addEqualTo("allDetailItemProperties.item.allProperties.value", "red");

rootCrit2.addAndCriteria(propCrit4);


rootCrit.addAndCriteria(rootCrit2);


Collection result = PersistenceBrokerFactory.defaultPersistenceBroker ().
	getCollectionByQuery(new QueryByCriteria(ItemImpl.class, rootCrit));

#############################

When i apply the alias to the root-criteria it seems that the portions "allDetailItemProperties" of the attribute paths
of propCrit1..4 get their own ITEMS-table joined instead of using the alias of the parent Criteria (rootCrit)

Maybe there is a way to configure the aliases with use of the class UserAlias, I tried everything without success.

Please help!

thx in advance,
Georg



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