How to query the database in an Entity Object (EO)

Question

I am using JDeveloper 11.1.2.2.0
I am Forms developer working in a new ADF project and need some help from the ADF gurus, I am just a ADF beginner.
Maybe hits question has a easy solution, but I don't know how to implement this:
I have simplified my scenario, but this is what I Need to do:
One database table DBTABLE with 3 columns (C1,N1,D1) C1-varchar2; N1-Numeric; D1-Date.
In the DBTABLE I have the following data:
ONE; 10; 01/10/2012
ONE; 20; 02/10/2012
TWO; 15; 02/10/2012
ONE; 15; 03/10/2012
I have created an ADF EO for the DBTABLE with all 3 attributes, then I have created another transient numeric attribute T1.
My requirement is when I create a new record and set attribute C1=ONE the transient attribute T1 should show sum(N1) from DBTABLE where D1>= 01/10/2012 and D1 < 03/10/2012.
In this case when I create a new record should the shown in T1 a total of 10+20 = 30.
I know how to use the EOImpl getters and setters, and how to set the T1 attribute when C1 is set. My problem is how to calculate the total T1.
How can I implement this in ADF? It is possible to implement this in the EO? It is possible to make the query select sum(N1) from DBTABLE where D1>= 01/10/2012 and D1 < 03/10/2012 and return the value to the EO attribute?
Thank you in advance

Answer 1

Hi Peter
Thank you for your suggestions, both of them are interesting but unfortunately they do not solve my problem, or at least I don’t know how.
I will try to better explain my problem
I have te table DBTABLE and another related table called DBDATES with colums(C1,DT1,DT2,TARGET) where I record periods of time and desired target. For instance my DBDATES table could have the following records
ONE; 01/01/2012; 31/01/2012; 100
ONE; 01/02/2012; 29/02/2012; 90
ONE; 01/03/2012; 31/03/2012; 95
TWO; 01/01/2012; 31/01/2012; 140
Exist a FK between both tables in the C1 column.
I have created an EO for the table DBTABLE with the tree persistent attributes (C1, N1, D1) an transient attribute (T1). The (C1,D1) is my DB primary key.
When I create a new record in the DBTABLE and based in the actual date I need to query the DBDATES table to check which is my TARGET and the valid target dates. For Instance if a record for person ONE is created on February 12, my TARGET is 90 from 01/02/2012 to 29/02/2012.
At the same moment I need to check the total amount of items record to the person ONE during the full target period.
Select sum(N1)
From DBTABLE
Where D1 between V2 and V3
And C1= V1;
Bind variables:
V1 = ‘ONE’;
V2 = ‘01/10/2012’ – queried from DBDATES
V3 = ‘03/10/201’ – queried from DBDATES
In resume, for a determined person when I create a new record in the DBTABLE I need to know their target for the actual period and how much as been record until now.
I don't know if is possible to solve this without using the View Objects, because I need to query the DBTABLE for a time frame and with bind variables.
Thank you in advance for your help.