Access Data from Database in Bean

ChristianM0147

Hello fellow programmers.

Im currently on the JDeveloper Version 12.2.1.4.0.

Can somebody please explain me how to access data from the Database in a bean?

I have an Application with 2 Components. An af:inputText and af:selectOneChoice. The af:inputText has an valueChangeListener that triggers a Method in a backing Bean with request scope. The af:inputText has also a binding to that bean.

I want to access my Database table with the value given in the af:inputText in the valueChangeListener Method. I already created the EntityObject and ViewObject for that table and I know how to access the value inserted in the af:inputText but i dont know how to access the ViewObject/EntityObject in the bean.

I want something like: "Select city from citys where postcode = af:inputText". With that Data i want to populate the af:selectOneChoice Component.

What needs to be considered is, that postcode is not the primary Key so methods like findByKey wont work.

Can i make this using EntityObjects/ViewObjects or do i need to manually open a Database Connection, create a Statement and execute the Query that way?

What is the ADF way to do it?

Timo Hahn

You don't access hte VO/EO directly in a bean. This breaks the MVC pattern. You can call a method in an application module or VO and get the right data.

Here is a sample of how to do this

https://tompeez.wordpress.com/2013/04/07/using-one-viewobject-for-global-lookup-data-part-2/ and the code you can get from here https://github.com/tompeez/BlogStaticVOLov_V3/archive/refs/heads/develop.zip

The type you enter in the first inputtext is used to filter the data for the LOV (lookupId).

Timo

Billy Verreynne

The type you enter in the first inputtext is used to filter the data for the LOV (lookupId).

I speed read this as "lookstupid". Then realised that Timo will not use this phrase, and read it again... 😂

ChristianM0147

@Timo Hahn Thats a really good blog for my use case, thank you.

But in generell, can you explain or send me information about how to access data from a bean via VO?

What i tried so far: Made a selectMethod in the ViewObjImpl and exposed it to the client so now i can instantiate a ViewObject in the bean and call that method. Is that the right way to do it?

Timo Hahn

Again:

You don't access hte VO/EO directly in a bean. This breaks the MVC pattern. You can call a method in an application module or VO and get the right data.

It's not how the framework works. For the given use case this is not needed anyway. Do you have another use case?

If so, tell us about it and we can discuss how to implement it.

I will not encourage you to get a VO into a bean without a good reason.

Timo