Wednesday, February 12, 2014

Collecting Changed Row Keys in ADF BC DoDML Method

If you ever had a question - how to collect information about all changed rows in the transaction, I will provide an answer in this post. As you perhaps already know, doDML method from Entity Implementation class is invoked per each changed row. This means our task is to collect Primary Keys for all changed rows and later access this collection from another method, to be able to process collected keys (log them, call PL/SQL, etc.).

Sample application -, overrides doDML method and collects all changed rows for Employees EO. In real use case, this should be more generic, if you want to apply similar logic for different EO's, however you should follow the same concept as described here. In doDML I collect information about Primary Key programmatically, getting key value and saving it in collection. Later this collection is stored in ADF BC session user data. There is no need to passivate collection with changed rows Primary Keys, as we are going to access it in the same request from afterCommit method on VO level - there will be no passivation in between:

I'm using a trick to get information about Entity primary key programmatically. There is a method called getPrimaryKeys in Entity Definition class, but this method is marked as protected, so I can't access it from custom code. However, I can implement my own Entity Definition class, override getPrimaryKeys protected method inside custom public method - in such way, I will make it available for custom methods:

doDML is invoked for every changed row, we need a method to be called at the end, to access collected info. Such method could be - afterCommit in View Object Implementation. This method is called after all rows are processed in doDML. I'm getting information about Primary Key and accessing ADF BC user data variable, where Primary Keys for all changed rows are stored. In this example, I'm simply printing out keys for all changed rows:

Here we can see, how it works. Change data in multiple rows and press Save:

Information about Primary Key name and values for every row containing changes is printed out:

We could use Primary Key values to access changed rows, process attributes we are interested in and call PL/SQL if required, using attribute values as parameters.

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