On 09/09/2005, at 3:39 AM, Chuck Hill wrote:
On Sep 8, 2005, at 12:21 AM, Ian Joyner wrote:
I'm having a strange problem fetching from tables using horizontal inheritance. I have a hierarchy with Skills_test at the root and subclasses Graded_test and Value_test. Doing a fetch on Skills_test, I expect all records in Graded_test and Value_test to be returned. I see the SQL on the server side and the report "9 row(s) processed, but get nothing on the server side:
NSArray /*[Skills_test]*/ tests = editingContext ().objectsWithFetchSpecification (new EOFetchSpecification ("Skills_test", null, null));
System.out.println (".load_test_tree tt " + tests.count ());
Suspecting deep fetching,
It should be deep by default.
Yes it was, I even printed out isDeep on the FS which showed true.
Sanity check: are there any PK values duplicated between the Graded_test and Value_test tables?
There were (shouldn't they be getting separate PKs anyway). So I reloaded the Value_test table with distinct PKs, but still it doesn't work.
Tool Curiosity: What is /*[Skills_test]*/ for. Looks like you are using some sort of tool.
No such luck. I just document what is expected to be in the array this way so if something weird comes out of it causing a ClassCastException you can double check. Of course with generic arrays, you don't have to put casts all over the place and never get ClassCastExceptions.
I changed this to just fetch on Graded_test:
NSArray /*[Skills_test]*/ tests = editingContext ().objectsWithFetchSpecification (new EOFetchSpecification ("Graded_test", null, null));
System.out.println (".load_test_tree tt " + tests.count ());
again seeing that fetches are made to the database, but nothing actually returned.
I then changed the fetch spec to retrieve any other table in the database and I get the correct number of rows returned, so it seems to be something weird with the Skills_test hierarchy. Can anyone give a clue as to why this code is returning records from every other table in the database except the ones I want? I'm sure it's something strange in the model (parents are set correctly, abstract is only on for Skills_test), but have not been able to pinpoint what the problem is.
That is a hard one. Have you specified restricting qualifiers on the entity in the EOModel that do not match what is in the DB? I can't think of anything else. I'll ruminate on it for a while.
There are no qualifiers. Since all subclasses only share the attributes name, number, and description, and all the other attributes are completely different, I'm using horizontal mapping. I'm sure I've just missed something really stupid, but it looks like it's a rebuild the model problem testing every step along the way until I find out.
The server side definitely loads the tables:
[2005-09-09 09:54:11 EST] <WorkerThread7> evaluateExpression: <com.webobjects.jdbcadaptor.OpenBasePlugIn$OpenBaseExpression: "SELECT t0.GRADE_SET_KEY, t0.PARENT_TEST_KEY, t0.PRIMARY_KEY, t0.TEST_DESCRIPTION, t0.TEST_NAME, t0.TEST_NUMBER FROM GRADED_TEST t0">
[2005-09-09 09:54:11 EST] <WorkerThread7> 33 row(s) processed
[2005-09-09 09:54:11 EST] <WorkerThread7> evaluateExpression: <com.webobjects.jdbcadaptor.OpenBasePlugIn$OpenBaseExpression: "SELECT t0.BEST_SCORE, t0.LOWER_IS_BETTER, t0.PARENT_TEST_KEY, t0.PRIMARY_KEY, t0.TEST_DESCRIPTION, t0.TEST_NAME, t0.TEST_NUMBER FROM VALUE_TEST t0">
[2005-09-09 09:54:11 EST] <WorkerThread7> 9 row(s) processed
but the output on the client side is:
[2005-09-09 09:54:11 EST] <AWT-EventQueue-0> .load_test_tree ao1 ()
[2005-09-09 09:54:11 EST] <AWT-EventQueue-0> .load_test_tree tt 0
Thanks
Ian