Controlling Entity posting order or commit order in ADF

Hi All,

In this blog I am going to show how you can control the entity posting order to database or in simple way you can say how we can control commit order of Entity Objects in ADF.



Scenario : Suppose if you have two table like EMPLOYEES and DEPARTMENTS. You have created Entity Object EmployeesEO and DepartmentsEO. Now in doDML INSERT method of the EmployeesEO you want to insert the row in DepartmentEO and commit it to database. Now if you have some trigger on EMPLOYEES table which is checking the newly inserted row and throwing error if it is not there.

Suppose your trigger code is like this:

  CREATE OR REPLACE TRIGGER "HR"."EMP_DEPT_TRG"

  BEFORE INSERT ON employees

  FOR EACH ROW

  DECLARE

  pcount NUMBER := 0;

  BEGIN



 IF (:NEW.DEPARTMENT_ID != 0) THEN

    SELECT COUNT(1)

         INTO pcount

         FROM DEPARTMENTS

        WHERE DEPARTMENT_ID = :NEW.DEPARTMENT_ID;



     IF (pcount = 0) THEN

        RAISE_APPLICATION_ERROR(-20006,'Department ID for this Employee is not existing.');

     END IF;

     else if (:NEW.DEPARTMENT_ID IS NULL) THEN

      RAISE_APPLICATION_ERROR(-20006,'Department ID for this Employee is not existing.');

      END IF;

  END IF;

  END;


So now when you try to insert the record in EMPLOYEES table from ADF and since there is no corresponsing DEPARTMENT_ID in the DEPARTMENTS table. It will throw the exception which is written inside the trigger as shown below:





Although I have written the code for inserting the record in DepartmentsEO but still it is throwing error as the data is not committed to DEPARTMENTS table and it is trying to insert the Employees record before department. So the trigger on department is getting failed and is throwing error.
Following is the code I have written in doDML method of EmployeesEO to insert record in DepartmentsEO.

    protected void doDML(int operation, TransactionEvent e) {

        if(null==getDepartmentId()){

                           setDepartmentId(getSequenceValue());

                           DepartmentsEOImpl deptRow=(DepartmentsEOImpl)getDepartmentsEO().createRow();

                            deptRow.setDepartmentId(getDepartmentId());

                            deptRow.setDepartmentName("TEST DEP");

                            getDepartmentsEO().insertRow(deptRow);                        }

        super.doDML(operation, e);

    }

    public Number getSequenceValue(){

            SequenceImpl seq=new SequenceImpl("DEPARTMENTS_SEQ",getDBTransaction());

            return seq.getSequenceNumber();

        }

So in this case we have to control the sequence or order of commit in EO. To do so we have to call the postChanges() method on DepartmentsEO before calling the super.doDML() method.
So our code will look like this in this case:

    protected void doDML(int operation, TransactionEvent e) {
        if(null==getDepartmentId()){
                           setDepartmentId(getSequenceValue());
                           DepartmentsEOImpl deptRow=(DepartmentsEOImpl)getDepartmentsEO().createRow();
                            deptRow.setDepartmentId(getDepartmentId());
                            deptRow.setDepartmentName("TEST DEP");
                            getDepartmentsEO().insertRow(deptRow);
                           deptRow.postChanges(e);
                        }
        super.doDML(operation, e);
    }

Now after calling this postChanges() method on DepartmentsEO it will ensure commit the record in Departments first and then it will commit the record in Employees.

 Now if you will try to insert the record in EmployeesVO then it will be successfully inserted.


That's all about it. 

Happy Coding :)

Comments

Post a Comment

Popular posts from this blog

Setting up the environment for Angular2 and Hello World Example in Angular2

Image
Hi All, In this post I am going you to show you how you can set up the environment for Angular2. You may want to run your application in different servers. So here I am going to show you how you can run your Angular2 application in the following two servers: 1. lite-server (static server) 2. Weblogic Server 10.3 Lets do the setup for lite server.  First of all go to any directory in your computer and create a folder in that directory with name "angular2-example". You can do it by the command line also by typing the following command. mkdir  angular2-example Now once the directory is created you need to create three files. 1. tsconfig.json 2. typings.json 3. package.json 1.  tsconfig.json This file is TypeScript compiler configuration file. It guides the compiler to generate JavaScript files after compilation. The content of this file will be as follows: {   "compilerOptions": {     "target": "es6",     "modu...
Read more

Showing number of rows or row count on top and bottom of table in ADF.

Image
Hi Friends, We will see today how to show the page count on top and bottom of table in ADF. I am assuming that you all know how to create the table to show data from view object in ADF. Assume you have a table which contains the information of employees from employees table of HR schema. Now surround this table with a panel collection. Now your panel collection has some facet with name "statusbar", "toolbar" etc. Right click on facet "toolbar" and select "insert after f : facet toolbar and then "Facet Secondary Toolbar" as shown below in image. Now on facet "statusbar" and "secondaryToolbar" put toolbar component from component pallet. Then put a output text inside each toolbar as follows:  <f:facet name="secondaryToolbar">             <af:toolbar id="t3" stretchId="s2">               <af:spacer width="10" height="10" id="s2...
Read more

Build a Simple ReactJS application using react-cli

Image
Hi All, In this blog we will see how we can create a sample application using react-cli.  It is a command line interface tool that seeks to automate some tasks when working on a React.js project. To starts with you have to install it globally by running following command: npm install -g react-cli The you have to run the following command in command window: npm install -g create-react-app  Now once it is installed you can create any directory where you want to create you sample ReactJS application. I have created a folder with name "TestApp" in my local drive. Now you have to run the following command to create the sample application. create-react-app testapp  While it is creating application and downloading all the artifacts related to this you can see the following things in command line as shown below: So it will create a ReactJS application with name "testapp" under folder "TestApp" as you can see in the above screenshot. On...
Read more