Cartesian join on 2 dimension tables, with count aggregation?

Hi, I have 2 dimension tables, Students, and Subjects, and a fact table, Marks. (simplified)
the Students and Subjects dimension tables both have a 1-N relationship with Marks, so reporting works fine.
However, there are some students who does not have a score in a certain Subject, so when I generate the report of each Subject's scores by Student it'll be
Subject Students Marks
English A 89
......... C 70
......... D 60
Maths B 30
......... C 80
because Students and Subjects are joined by the Marks table
What I'd like to see is
Subject Students Marks
English A 89
......... B 0
......... C 70
......... D 60
Maths A 0
......... B 30
......... C 80
......... D 0
The joins between the dimension and fact tables are all set to "Left-outer join" (where "left" is the dimension table)
I thought I needed a cartesian/cross join on Subjects and Students, using the dummy table technique here: http://gerardnico.com/wiki/dat/obiee/densification_repository#the_cross_join_between_the_dimensions
But it didn't work, not to mention that I have a feeling that this doesn't really apply to 10g or my problem.
Can someone point me in the right direction on this? Thanks!
Above problem solved, but I also need a column of "Count of students who scored 50 or less" which includes the students who did not have any scores. Adding the dummy column to my report breaks the aggregation in my report, while removing the column will take me back to square one.
How do I generate a report that does aggregation that takes into account the students with no scores?
Edited by: lum on 28-Mar-2012 20:13

Here's what I did:
I created the physical table with 1 column, and did a complex join with expression "1=1" on the 2 tables that my actual fact table was directly joined to (and none of the indirect joins). I'm using 11g, so to do complex joins I had to use Manage->Joins
Then I added the dummy column to my Marks fact table in the BMM layer by just dragging it and set the aggregation rule. And then to the presentation layer too.
After updating the repository onto the server, the table behaviour is still the same as before, and the dummy column didn't do anything and displayed a blank value.
Could it be because of my other joins that make this dummy join not work? I don't even know if this 1=1 complex join work in 11g....!
Has anyone tried this join technique in 11g? Thanks!
PS: My dimension table and fact tables are actually logical tables that join several tables at the logical table source layer. My dummy fact table just joins the most detailed layer of the physical dimension tables.

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Hi,
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the [Coal_Type].Coal_Type field.
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COAL SAMPLES TABLE
ID
mFrom
mTo
SAMPLE NUMBER
AD261
57
57.5
SAMPLE_001
AD261
57.5
58
SAMPLE_002
AD261
58
59
SAMPLE_003
AD261
59
60
SAMPLE_004
AD261
60
61
SAMPLE_005
AD261
61
62
SAMPLE_006
AD261
62
63
SAMPLE_007
AD261
63
64
SAMPLE_008
AD261
64
65
SAMPLE_009
AD261
65
66
SAMPLE_010
AD261
66
67
SAMPLE_011
AD261
67
68
SAMPLE_012
AD261
68
69
SAMPLE_013
AD261
69
70
SAMPLE_014
AD261
70
71
SAMPLE_015
AD261
71
72
SAMPLE_016
AD261
72
73
SAMPLE_017
AD261
73
74
SAMPLE_018
AD261
74
75
SAMPLE_019
AD261
75
76
SAMPLE_020
AD261
76
77
SAMPLE_021
AD261
77
78
SAMPLE_022
AD261
78
79
SAMPLE_023
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ID
Type_mFrom
Type__mTo
COAL TYPE
AD261
57
68.6
BROWN COAL
AD261
68.6
75
GREY COAL
AD261
75
78.2
BLACK COAL
AD261
78.2
79.2
BLACK COAL
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ID
mFrom
mTo
DOMINANT_COAL TYPE
AD261
57
57.5
BROWN COAL
AD261
57.5
58
BROWN COAL
AD261
58
59
BROWN COAL
AD261
59
60
BROWN COAL
AD261
60
61
BROWN COAL
AD261
61
62
BROWN COAL
AD261
62
63
BROWN COAL
AD261
63
64
BROWN COAL
AD261
64
65
BROWN COAL
AD261
65
66
BROWN COAL
AD261
66
67
BROWN COAL
AD261
67
68
BROWN COAL
AD261
68
69
BROWN COAL
AD261
69
70
GREY COAL
AD261
70
71
GREY COAL
AD261
71
72
GREY COAL
AD261
72
73
GREY COAL
AD261
73
74
GREY COAL
AD261
74
75
GREY COAL
AD261
75
76
BLACK COAL
AD261
75
76
BLACK COAL
AD261
76
77
BLACK COAL
AD261
77
78
BLACK COAL
AD261
78
79
BLACK COAL
Can you please help with the logic of this query?
Thanks very much.

Well, here is the beginning of the solution:
;with cte as (select S.*, T.[Coal Type] as [Dominant_Coal],
case when
T.m_from between S.m_from and S.m_to
AND T.m_to between S.m_from and S.m_to then 0
when T.m_from between S.m_from and S.m_to then t.m_from - S.m_from
else S.m_to - T.m_to end as [Diff]
from Coal_Samples S LEFT JOIN Coal_Type T
ON T.m_from between S.m_from and S.m_to
OR T.m_to between S.m_from and S.m_to),
cte1 as (select *, row_number() over (partition by cte.ID order by Diff) as Rn
from cte)
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Hi all,
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Hi Veeravalli,
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Hi Saleem
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TG

Cartesian join on 2 dimension tables, with count aggregation?

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