Update ProductTrees_Lines - specific position

Question

Hi everybody,
I want to update a specific position in ProductTrees_Lines with B1if scenario. For example I have a product tree for masteritem with 3 entries.
masteritem
1. detail item1, 2 pcs
2. detail item2, 3 pcs
3. detail item3, 4 pcs
Now I want to update position 2 with 100 pcs.
So my update structure for B1 object call (object id 66) looks like this:
<QueryParams>
     <Code>masteritem</Code>
</QueryParams>
<ProductTrees>
     <row />
</ProductTrees>
<ProductTrees_Lines>
     <row/>
     <row>
          <ItemCode>detail item2</ItemCode>
          <Quantity>100.0</Quantity>
     </row>
     <row/>
</ProductTrees_Lines>
In fact I need to list the <row>-tags proper to the positions. Isn´t there a easier way by using something like <childnum> (which is the name of the field in the database describing the position of the productTree_line), so I don´t have to list all <row>-tags (reducing the xml I need to write)?
Using <childnum> leads to an error. And I can´t find a adequate field in the object description for object id 66.
Any suggestions?
Best regards
Benjamin

Answer 1

Hello Benjamin,
no, unfortunately not (I do not know). the Object help from b1iF says:
<BOM>
    <!--DB Table Name: -->
    <BO>
        <!--multiple such elements are allowed-->
        <AdmInfo>
            <Object>long</Object>
            <Version>long</Version>
        </AdmInfo>
        <QueryParams>
            <TreeCode>string</TreeCode>
        </QueryParams>
        <ProductTrees>
            <row>
                <!--multiple such elements are allowed-->
                <TreeCode>string</TreeCode>
                <TreeType>string</TreeType>
                <Quantity>double</Quantity>
                <DistributionRule>string</DistributionRule>
                <Project>string</Project>
                <DistributionRule2>string</DistributionRule2>
                <DistributionRule3>string</DistributionRule3>
                <DistributionRule4>string</DistributionRule4>
                <DistributionRule5>string</DistributionRule5>
                <PriceList>long</PriceList>
                <Warehouse>string</Warehouse>
            </row>
        </ProductTrees>
        <ProductTrees_Lines>
            <row>
                <!--multiple such elements are allowed-->
                <ItemCode>string</ItemCode>
                <Quantity>double</Quantity>
                <Warehouse>string</Warehouse>
                <Price>double</Price>
                <Currency>string</Currency>
                <IssueMethod>string</IssueMethod>
                <Comment>string</Comment>
                <ParentItem>string</ParentItem>
                <PriceList>long</PriceList>
                <DistributionRule>string</DistributionRule>
                <Project>string</Project>
                <DistributionRule2>string</DistributionRule2>
                <DistributionRule3>string</DistributionRule3>
                <DistributionRule4>string</DistributionRule4>
                <DistributionRule5>string</DistributionRule5>
                <WipAccount>string</WipAccount>
                <ItemType>long</ItemType>
                <LineText>string</LineText>
                <AdditionalQuantity>double</AdditionalQuantity>
            </row>
        </ProductTrees_Lines>
    </BO>
</BOM>
theres no LineNum or other primary key