Passing an argument in the SQL Query of a View Object

Question

Hi,
It is possible that this question has been asked before, however I have searched for a half an hour in the forums and couldn't find a solution.
I am also new to using JDeveloper and ADF. Here's the situation:
I am developing an application that doesn't have to do anything else then displaying data from a database. Pretty straightforward actually.
Now I have made a vew pages with several collapsible panels (af:showDetailHeader) and have setup the datasources (or so I thought).
All that remains is:
- drag & drop a view object, from the application module that I created, onto the collabsible panels, so a child element gets created which displays data from the database.
- hack the layout so it looks like I want it to.
The problem that I have is the following:
I am using a 'User'-class that contains values I need when quering the database.
That User-object is part of a user-session.
What I want, for example, is to use the 'getPersonId()' function of that User-object and pass the argument to a SQL-query of a certain view-object.
The query would become something like:
'SELECT * FROM people WHERE people.personId = :someNumber'.
Now I've read some stuff about variable binding, which is complemented by something like (backing bean code):
getDBTransaction().getRootApplicationModule().getACertainViewObject().setWhereClauseParameter(1, user.getPersonId());
The examples I have found that might match my wishes are not using business components, but EJB's. I am having difficulty with understanding the 'how'-part of variable binding.
Also, I do not know enough of ADF to be able to create a situation like:
'User loads page, collapsible panel 1 is fully shown, the others are undisclosed.'
(meaning, that for panel1 a query has been executed.)
'User clicks on collapsible panel 2 which triggers a backingbean that somehow retrieves data from a view object'.
I would appreciate any help that somebody can give.
If it is not too much of a problem, please provide code snippets in case you have a solution. I am new to ADF :(.
-edit
I am using JDeveloper 10.1.3.3.0 in case that is of any importance.
Message was edited by:
Hugo Boog

Answer 1

Hello Stijn,
I didn't think about a referenced bean rule in the faces-config.
I added it right away and I am now able to set parameters of a View-object, not using a page button and before the page loads. You made my day!
In case anyone ever reads this post again, the summary of how to generate a table based on a View-object using dynamic parameters.:
1a: Go to faces-config.xml -> Overview tab'
1b: Go to the menuitem "Referenced Beans"
1c: Click on 'new' and select the existing bean you want to access data from and input a name. In this example I use name="user"
2: Create a View-object using the wizard.
2a: Specify the query you want in the menuitem 'SQL Statement'.
Add the 'parameters' you want to. You will have something like:
"SELECT * FROM someTable WHERE table.columnname LIKE :someArgument".
- hint: if you want the result to become something like:
"SELECT * FROM someTable WHERE table.columnname LIKE '%someArgument%'" then you have to add the '%'-characters in your code itself (read: someClass.setParameter("%" + someArgument);).
2b: In the menuitem 'Bind Variables' you have to add the variables you are referring to in the query. If you look at the query in 2a, then you have to add a variable with name "someArgument".
2c: Add the View-object to a Application Module (create one if nessecairy).
3a: Open a .jsp(x) file. Drag the View-object created in step 2 from the 'Data Controls'-pane to the page.
3b: Click on the '+' of the View-object in the 'Data Controls'-pane and open 'Operations' and drag 'ExecuteWithParams' to your page as a button.
3c: We do not want to use a button, the action has to be executed immediatly. So In the page source remove the lines that were created after dropping 'ExecuteWithParams'.
3d: Right-click on the page and select "Go to Page Definition".
3e: Go to the action id that is called 'ExecuteWithParams#', where # is a number.
Change the id to something useful.
3f: Change the NDValue so it corresponds with the value you want.
Example:
<action id="getAddressData" IterBinding="AddressesView1Iterator"
InstanceName="MyHRServiceModuleDataControl.AddressView1"
DataControl="MyHRServiceModuleDataControl" RequiresUpdateModel="true" Action="95">
<NamedData NDName="someArgument" NDType="java.lang.String"
NDValue="#{user.personId}"/>
</action>
Note: It is possible to use the value of a Backing Bean in NDValue.
Note 2: user is the bean I referred to in the faces-config.xml!
3g: Under the executables item, add an 'invokeAction' to pass the parameter to the View-object before your JSP-file loads:
<executables>
<invokeAction Binds="getAddressData"
id="loadAddressDataOfPersonIdInSession"
Refresh="prepareModel"/>
Thank Stijn Haus for this :)