JSP, DataWebBean: How to dynamically set the where clause of query and display record

Question

Hi,
I am reposting this question as per suggestions made by Mr. Dwight.
I have used ViewCurrentRecord web bean to display records from EMP table. I have to use the Dept_Id_FK from the current
record of the EMP table to display corresponding records of Dept table. I have a view object called DeptView in my Business
Components which selects all the records from the Dept table.
How do I get the value of Dept_Id_FK and use it to display the required records of the Dept table?
I tried to declare a variable and get the value of Dept_Id_FK but it did not work. My code is as follows:
<%! String m_DeptId = null; %>
<jsp:useBean id="RowViewer" class="oracle.jbo.html.databeans.ViewCurrentRecord" scope="request">
<%
RowViewer.initialize(pageContext, "EMPApp_EMP_EMPAppModule.EMPView1");
RowViewer.setReleaseApplicationResources(false);
RowViewer.getRowSet().next();
m_DeptId = (String)RowViewer.getRowSet().getCurrentRow().getAttribute("DeptIdFk");
%>
</jsp:useBean>
Thanks.
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Answer 1

First of all, Thank you very much for making use of the new topic format. It is very much appreciated.
As for your question, I think there are several different ways to accomplish what I think you want to do.
1. Create a view object that includes both Emp and Dept entities and join them there. In this case, your query would look something like this:
Select e.empno,e.name,...,d.dname,d.loc from emp e, dept d
where e.deptno = d.deptno
You should be able to create a JSP off of this view object that contains both the employee and department information. In this case, BC4J takes care of the foreign key to primary key coordination.
2. In order to set a dynamic where clause for a view, you need to do the following in your usebean tag:
rsn.initialize(application,session, request,response,out,"DeptView");
rsn.getRowSet().getViewObject().setWhereClause("deptno=" &#0124; &#0124; m_DeptId);
rsn.getRowSet().getViewObject().executeQuery();
rsn.getRowSet().first();
You will need to do this in a separate usebean tag from the EmpView, since the usebean can only initialize one view object.
In other words, you would have your ViewCurrentRecord bean tag for the EmpView, then a separate one for the DeptView where you use the above code to set the where clause to display just the information for the department you want.
Another option, but one I'm not sure would work as well, is to create a master-detail JSP to do this for you. Usually a master-detail is a one-to-many (one department to many employees). Your request appears to be the reverse, but might still be doable using the same mechanism.
You set up relationships between views in your BC4J project using View Links. If you used the BC4J project wizard and created default views, some of these links may have been created for you. They are created when BC4J detects a foreign key to primary key relationship in the database.
You can create your own View Links using the View Link wizard. Select your BC4J project node and choose Create View Link... from the context menu. You will be asked to select a source view (Emp), and a target view (Dept), then select the attribute in each view that related the two of them (deptno).
Next, you need to reflect this new relationship setting in your application module. Select your app module and choose Edit from the context menu. On the data model page, select the EmpView node in the Selected list. Now select the DeptView node in the available list and shuttle it over. You should see DeptView1 via yourlink appear indented under the EmpView node. Save and rebuild your BC4J project to reflect the changes.
In your JSP project, you can now have the wizard create a master-detail form for you based on DeptView1.
Let me know if the above answers your question, or if I have misunderstood what it is you wanted to do.
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