Re: [castor-dev] update in one transaction

Mon, 05 Jan 2004 02:21:33 -0800

Hi Roger,
 
what about the following code:
 
// start transaction
db.begin();
// load detail
DDD ddd = (DDD)db.load(DDD.class, new Long(1000));
// set detailstatus to 1
ddd.setDetailstatus(1);         //the original value was 0
// get master of the detail changed
MMM mmm = ddd.getMaster();
 
// get iterator over all details of the master
Iterator iter = mmm.getDetails().iterator();
 
// iterate over details until one is 0
int masterstatus = 1;
while ((masterstatus == 1) && (iter.hasNext()))
     if (((DDD)iter.next()).getDetailstatus() == 0) masterstatus = 0;
 
// set masterstatus
mmm.setMasterstatus(masterstatus);
 
// comit transaction
db.commit();
 
// close database
db.close();
Regards
Ralf
 
----- Original Message -----
From: ??
Sent: Friday, January 02, 2004 5:06 AM
Subject: Re: [castor-dev] update in one transaction

Hi Werner,
 
Maybe I didn't exactly tell what I mean.
I have a true case here:
 
Table "MMM" is the master table and table "DDD" is the detail table.
There is a field named "detailstatus" on "DDD".
Also, there is a field named "masterstatus" on "MMM".
They can all have two values, one is "0", the other is "1".
The initial values are all 0.
 
The logic is like this:
Every time I change a "DDD" record's "detailstatus" from 0 to 1.
Just after this operation, I check its master record's all detail records(including the record which I just operated)
to see whether all the "detailstatus" equals to 1. If this is true, I will change the "masterstatus" from 0 to 1.
 
With JDBC, I can use sql "update DDD set detailstatus = 1 where dddid = XXX",
then "select count(*) cnt from DDD where mmmid = XXXX and detailstatus <> 1" to get what I need.
But with Castor JDO, I can only use the setDetailstatus(1) to change the value.
Actually, this has done nothing on the DATABASE.
So the following OQL "select t from DDD t where t.detailstatus <> 1" will give me wrong result, except I call commit() before the OQL.
Obviously, using two transactions may cause problems.
 
So, I think there may have defect when update in one transaction for one cannot get the changed value using OQL.
 
Thanks,
Roger
 
 
 
----- Original Message -----
Sent: Friday, December 12, 2003 8:50 PM
Subject: Re: [castor-dev] update in one transaction

Roger,

looking at the code fragment below, everything looks fine to me. In order to have a more thorough look at your problem, can you please post the relevatn parts of your mapping file and the SQL schema if possible.

Ideally, it would be very nice if you coul�d wrap up everything with an Ant build file, and transform the below code fragment to a JUnit test case.

Werner

I am a bit surprised to see that --Original Message Text---
From: ����
Date: Thu, 11 Dec 2003 15:53:58 +0800

Hi all,

Please see the code:

Database db = JdoUtils.createJdoDb();

db.begin();

Student student = (Student)db.load(Student.class, new Long(1000));

student.setPassed(1);//the original value was 0

//here, I do not commit;

OQLQuery oql = db.getOQLQuery("select s from Student where s.passed = 0 and s.studentid = 1000");
results = oql.execute();

if (results.hasMore()){//It will have true value and I can still get the Student, BUT the value of field "passed" has become 1
System.out.println("there is an error.");
}
else{
//other data operation
}

db.commit();

db.close();

This is a common problem which brings me big trouble.
Is this a bug? Or can I have alternative code?

Thanks,
Roger




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