The techniques for populate a sequence attribute in Oracle ADF

Technique No1:   

Allowing the database to handle the insertion operation

1- Add trigger to DB Table to fetch next sequence' number

2- Open Entity Object (ex:Department)

3- Change type of DepartmentId attribute to DBSequence

Technique No2 : 

Fetching the next sequence number using Java/Groovy

first we need to add a java method to get thenext sequence' No

• Open Department Entity Object
• Go to Java ==>> Edit Java Option 
• Check Generate Entity Object Class

• Open DepartmentsImpl Java file 
• Add the following lines to end of the file

To Get the next sequence number at the time of record creation (Java code):

• Open DepartmentsImpl Java file
• Go to Source Menu ==>> Override Methods
• check create method

Add the following line after create  method 

To Get the next sequence number at the time of record creation (Groovy) : 

 ( read Introduction to Groovy by Grant Ronald )

• Open Departments Entity Object
• Go to DepartmentId
• Choose Expression in Default Value section
• Enter adf.object.nextSequenceVal("DEPARTMENTS_SEQ")

 
To Get the next sequence number at the time of Commit (Java Code) : 
used to avoid gaps between sequence number 

• Open DepartmentsImpl Entity Object
• Go to Java tab 
• Check Data Manipulation Methods 

•  Add the following to doDML methods
  
  
  

Question:if i am in need to apply EMPLOYEES SEQ to Employee Id,do i need to add nextSequenceVal method in the Employees EO again ?

Answer : Yes, but can you think of a more general way to extend ADF Framework Classes where you can add your favorite utilities

To add our custom ADF Framework Classes:

• Right click on TestSeqModel 
• java ==>>Class
• Enter EntityImpl for Name 
• Enter model.extension for Package
• Enter oracle.jbo.server.EntityImpl for Extends

• Add nextSequenceVal method

 

• Double click on TestSeqModel 
• Go to ADF Business Component ==>> Base Classes
• In Entity Object Section  , browse for Row 
• Enter entity word in the search menu
• Choose model.extension

• Press Ok and again OK 
• Remove nextSequenceVal method from Departments EO 
• The nextSequenceVal method is available now to all Entity Objects
• Use nextSequenceVal in Employees EO
  

read  How to populate ids using dbsequence in Oracle ADF only during database commit   by Ravi Nuka

Technique No3 :

Nick Haralabidis spoke about using a custom property to populate a sequence attribute in his book Oracle JDeveloper 11gR2 Cookbook 

The best solution for me is the third one