...
| Excerpt |
|---|
January 15, 2007 |
This technical article was generously contributed by Chris Webb, an OLAP guru and independent consultant (check him out at Crossjoin Consulting, or on his blog). Chris also has written a book on MDX called 'MDX Solutions', that you can get here once you are looking to go deep with Mondrian and MDX!
In the last two articles in this series we've focused on creating some common types of calculation in MDX. However, creating calculations isn't the only problem you'll face when creating business intelligence reports: you need to be able to define your queries appropriately too so you see the information you want. In this article we'll look at the ways you can manipulate sets in MDX in order to do this.
Resources Before You Get Started
To run the queries that Chris presents in this technical article, you will need JPivot, hooked up to the SteelWheelsSales sample cube. You can get both of these pre-configured and ready to use out of the box in the Pentaho Pre-configured Installation (PCI). Just navigate to the Steel Wheels Analysis Samples, and select the MDX Query button from the JPivot toolbar.
- Pentaho Pre-configured Installation (PCI) running locally, and the hypersonic database running locally with the SampleData database, version 1.2 or later.
Overview
First of all, though, what is a set? A set is an ordered list of either members or tuples (if you're not sure what a member or a tuple is it might be helpful to reread the first article in this series on 'Previous Period Growths') and is written in MDX as a comma-delimited list of uniquenames or tuples enclosed in curly brackets. Here's an example of a set of members:
| Code Block |
|---|
{[Time].[All Years].[2003], [Time].[All Years].[2004], [Time].[All Years].[2005]\} {code} |
And
...
here's
...
an
...
example
...
of
...
a
...
set
...
of
...
tuples:
...
| Code Block |
|---|
\{([Measures].[Sales],[Markets].[All Markets].[EMEA]), ([Measures].[Sales],[Markets].[All Markets].[APAC])\} {code} h3. MDX Queries By Example When |
MDX Queries By Example
When you're
...
writing
...
a
...
SELECT
...
statement
...
in
...
MDX
...
you
...
use
...
sets
...
to
...
specify
...
which
...
data
...
appears
...
on
...
which
...
axis
...
in
...
your
...
query.
...
So,
...
for
...
example,
...
we
...
can
...
take
...
the
...
first
...
set
...
above
...
and
...
put
...
it
...
on
...
the
...
columns
...
axis
...
in
...
a
...
query
...
and
...
take
...
the
...
second
...
set
...
and
...
put
...
it
...
on
...
rows,
...
and
...
the
...
resulting
...
SELECT
...
statement
...
would
...
look
...
like
...
this:
...
| Code Block |
|---|
select \{[Time].[All Years].[2003], [Time].[All Years].[2004], [Time].[All Years].[2005]\} on columns, \{([Measures].[Sales],[Markets].[All Markets].[EMEA]), ([Measures].[Sales],[Markets].[All Markets].[APAC])\} on rows from [SteelWheelsSales] {code} Run this query and you'd see the following: \\ \\ !sets1.JPG! \\ As noted above, a set is an ordered list and the members or tuples appear on the axis in the order they are specified in the set. There are several MDX functions available which mean you don't always have to write out every member's unique name in your sets by hand. Probably the most common is the Members function which will return all the members on either a dimension or on a level in a dimension. Here's an example query which returns all the Months on the Time dimension on rows: |
Run this query and you'd see the following:
As noted above, a set is an ordered list and the members or tuples appear on the axis in the order they are specified in the set.
There are several MDX functions available which mean you don't always have to write out every member's unique name in your sets by hand. Probably the most common is the Members function which will return all the members on either a dimension or on a level in a dimension. Here's an example query which returns all the Months on the Time dimension on rows:
| Code Block |
|---|
select
{[Measures].[Sales]}
on columns,
{[Time].[Months].Members}
on rows
from [SteelWheelsSales]
|
To
...
use
...
the
...
Members
...
function
...
you
...
simply
...
give
...
the
...
unique
...
name
...
of
...
the
...
dimension
...
or
...
level
...
(in
...
the
...
example
...
above,
...
the
...
unique
...
name
...
of
...
the
...
Months
...
level
...
on
...
Time
...
is
...
[Time
...
].
...
[Months
...
])
...
and
...
add
...
.Members
...
onto
...
the
...
end
...
of
...
it.
...
Other
...
common
...
functions
...
include
...
the
...
Children
...
and
...
Descendants()
...
functions
...
which
...
we
...
came
...
across
...
earlier
...
in
...
this
...
series,
...
both
...
of
...
which
...
return
...
the
...
set
...
of
...
members
...
'underneath'
...
a
...
given
...
member
...
in
...
a
...
dimension.
...
Here's
...
an
...
example
...
of
...
the
...
.Children
...
function
...
which
...
shows
...
all
...
of
...
the
...
Quarters
...
in
...
the
...
Year
...
2004:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
{[Time].[All Years].[2004].Children}
ON ROWS
from \[SteelWheelsSales
|
All
...
of
...
these
...
functions
...
return
...
sets
...
of
...
members,
...
but
...
what
...
about
...
creating
...
sets
...
of
...
tuples?
...
This
...
is
...
where
...
another
...
very
...
common
...
function,
...
Crossjoin(),
...
comes
...
in:
...
it
...
takes
...
two
...
sets
...
of
...
members
...
from
...
different
...
dimensions,
...
performs
...
a
...
cartesian
...
product
...
and
...
returns
...
a
...
set
...
of
...
tuples
...
containing
...
every
...
single
...
possible
...
combination
...
of
...
members
...
from
...
each
...
set.
...
So,
...
logically,
| Code Block |
|---|
Crossjoin ( {a1, a2} , {x1, x2} ) |
will
...
return
...
the set
| Code Block |
|---|
{(a1, x1), (a1, x2), (a2, x1), (a2, x2)}
|
.
...
Here's
...
an
...
example
...
which
...
returns
...
all
...
possible
...
combinations
...
of
...
Years
...
and
...
Markets
...
on
...
rows:
| Code Block |
|---|
select
{[Measures].[Sales]} ON COLUMNS,
crossjoin(
[Time].[Years].Members,
[Markets].[All Markets].Children)
ON ROWS
from [SteelWheelsSales]
|
Now
...
we've
...
got
...
our
...
sets,
...
let's
...
do
...
something
...
useful
...
with
...
them.
...
For
...
instance
...
we
...
might
...
want
...
to
...
sort
...
the
...
items
...
in
...
the
...
set
...
in
...
a
...
particular
...
order,
...
and
...
to
...
do
...
that
...
we
...
need
...
to
...
use
...
the
...
Order()
...
function.
...
Order()
...
takes
...
three
...
parameters:
...
the
...
set
...
you
...
wish
...
to
...
sort,
...
the
...
MDX
...
expression
...
you
...
wish
...
to
...
use
...
to
...
sort
...
by,
...
and
...
whether
...
you
...
want
...
to
...
sort
...
in
...
ascending
...
or
...
descending
...
order.
...
Here's
...
an
...
example
...
that
...
sorts
...
all
...
of
...
our
...
Years
...
by
...
Sales:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,order(
[Time].[Years].Members,[Measures].[Sales],bdesc)
ON ROWS
from [SteelWheelsSales]
|
The
...
second
...
parameter,
...
the
...
MDX
...
expression
...
you
...
wish
...
to
...
order
...
by,
...
can
...
either
...
return
...
a
...
numeric
...
value
...
or
...
a
...
string
...
value.
...
In
...
the
...
example
...
above
...
we
...
used
...
the
...
Sales
...
measure
...
but
...
we
...
could
...
equally
...
have
...
used
...
a
...
tuple,
...
and
...
it's
...
important
...
to
...
remember
...
that
...
this
...
expression
...
is
...
independent
...
of
...
anything
...
we
...
are
...
displaying
...
on
...
columns.
...
So,
...
for
...
instance
...
the
...
following
...
query
...
shows
...
Years
...
ordered
...
in
...
the
...
same
...
way
...
as
...
in
...
the
...
previous
...
query
...
even
...
though
...
the
...
ordering
...
does
...
not
...
reflect
...
the
...
values
...
actually
...
displayed
...
in
...
the
...
grid:
| Code Block |
|---|
select {([Measures].[Sales], [Markets].[All Markets].[Japan])} ON COLUMNS, Order([Time].[Years].Members, [Measures].[Sales], BDESC) ON ROWS from [SteelWheelsSales] |
This
...
can
...
be
...
pretty
...
confusing
...
for
...
people
...
new
...
to
...
MDX
...
'
...
we
...
are
...
sorting
...
by
...
Sales
...
at
...
the
...
[All
...
Markets
...
]
...
level
...
but
...
displaying
...
Sales
...
for
...
Japan.
...
If
...
we
...
wanted
...
to
...
sort
...
by
...
the
...
values
...
we're
...
seeing
...
in
...
this
...
query,
...
we'd
...
need
...
to
...
explicitly
...
state
...
that
...
we
...
wanted
...
to
...
sort
...
by
...
Sales
...
for
...
Japan
...
by
...
using
...
a
...
tuple
...
in
...
the
...
second
...
parameter:
| Code Block |
|---|
select {([Measures].[Sales], [Markets].[All Markets].[Japan])}
ON COLUMNS,
Order([Time].[Years].Members, ([Measures].[Sales],
[Markets].[All Markets].[Japan]), BDESC)
ON ROWS
from [SteelWheelsSales]
|
There's
...
one
...
last
...
thing
...
to
...
notice
...
about
...
the
...
Order()
...
function,
...
and
...
that's
...
the
...
'b'
...
in
...
front
...
of
...
the
...
'desc'
...
in
...
the
...
last
...
parameter.
...
This
...
'b'
...
stands
...
for
...
'break
...
the
...
hierarchy':
...
without
...
it
...
Order
...
will
...
first
...
sort
...
the
...
member
...
in
...
the
...
set
...
you
...
pass
...
in
...
into
...
hierarchical
...
order
...
and
...
then
...
sort
...
by
...
the
...
criteria
...
you
...
specify.
...
You
...
can
...
see
...
what
...
this
...
does
...
by
...
running
...
the
...
two
...
queries
...
which
...
show
...
all
...
Months
...
sorted
...
by
...
name
...
'
...
the
...
first
...
breaks
...
the
...
hierarchy,
...
so
...
that
...
you
...
see
...
all
...
the
...
Septembers,
...
then
...
all
...
the
...
Octobers,
...
then
...
all
...
the
...
Novembers
...
and
...
so
...
on,
...
while
...
the
...
second
...
retains
...
the
...
hierarchy
...
so
...
you
...
see
...
all
...
the
...
Months
...
for
...
2003
...
sorted
...
by
...
name,
...
then
...
all
...
the
...
Months
...
for
...
2004
...
sorted
...
by
...
name
...
and
...
all
...
the
...
Months
...
for
...
2005
...
sorted
...
by
...
name.
| Code Block |
|---|
select
{([Measures].[Sales], [Markets].[All Markets].[Japan])}
ON COLUMNS,
Order([Time].[Months].Members, [Time].CurrentMember.Name, BDESC)
ON ROWS
from [SteelWheelsSales]select {([Measures].[Sales], [Markets].[All Markets].[Japan])}
ON COLUMNS,
Order([Time].[Months].Members, [Time].CurrentMember.Name, DESC)
ON ROWS
from [SteelWheelsSales]
|
Another
...
thing
...
we
...
might
...
want
...
to
...
do
...
with
...
our
...
set
...
is
...
filter
...
it
...
somehow.
...
Looking
...
the
...
query
...
we've
...
just
...
run
...
we
...
can
...
see
...
that
...
there
...
are
...
several
...
rows
...
with
...
no
...
values
...
and
...
we
...
might
...
want
...
to
...
remove
...
those
...
rows
...
from
...
the
...
resultset.
...
The
...
easiest
...
way
...
to
...
do
...
is
...
to
...
add
...
NON
...
EMPTY
...
before
...
the
...
beginning
...
of
...
our
...
row
...
axis
...
definition,
...
as
...
follows:
| Code Block |
|---|
select
{([Measures].[Sales], [Markets].[All Markets].[ Japan ])}
ON COLUMNS,
NON EMPTY Order([Time].[Months].Members, [Time].CurrentMember.Name, DESC)
ON ROWS
from [SteelWheelsSales]
|
NON
...
EMPTY
...
has
...
removed
...
all
...
rows
...
where
...
every
...
value
...
on
...
that
...
row
...
is
...
a
...
null,
...
and
...
if
...
we
...
added
...
it
...
to
...
the
...
columns
...
axis
...
it
...
would
...
do
...
the
...
same
...
there.
...
To
...
implement
...
more
...
demanding
...
filter
...
criteria,
...
though,
...
we
...
need
...
to
...
use
...
the
...
Filter()
...
function.
...
It
...
takes
...
two
...
parameters:
...
the
...
set
...
you
...
wish
...
to
...
filter
...
and
...
an
...
MDX
...
expression
...
which
...
returns
...
a
...
Boolean
...
value
...
which
...
will
...
be
...
evaluated
...
for
...
every
...
item
...
in
...
the
...
set.
...
Here's
...
an
...
example
...
which
...
only
...
returns
...
Months
...
where
...
Sales
...
is
...
greater than 500000:
| Code Block |
|---|
select {[Measures].[Sales]} ON COLUMNS, Filter( Order([Time].[Months].Members, [Time].CurrentMember.Name, DESC) , ([Measures].[Sales] > 500000.0)) ON ROWS from [SteelWheelsSales] |
This
...
also
...
illustrates
...
the
...
fact
...
that
...
you
...
can
...
nest
...
functions
...
like
...
Filter()
...
and
...
Order()
...
which
...
take
...
a
...
set
...
as
...
one
...
of
...
their
...
parameters
...
and
...
return
...
a
...
set.
...
Another
...
common
...
type
...
of
...
filter
...
is
...
the
...
'top
...
n',
...
for
...
example
...
where
...
you
...
want
...
to
...
return
...
your
...
top
...
ten
...
best-selling
...
products.
...
MDX
...
provides
...
the
...
Topcount()
...
function
...
to
...
allow
...
you
...
to
...
do
...
this
...
(there
...
is
...
also
...
a
...
Bottomcount()
...
function
...
which
...
finds
...
the
...
'bottom
...
n',
...
a
...
Toppercent()
...
function
...
which
...
finds
...
the
...
'top
...
n%'
...
and
...
a
...
Bottompercent()
...
function)
...
and
...
it
...
takes
...
three
...
parameters:
...
the
...
set
...
you
...
wish
...
to
...
filter,
...
the
...
number
...
of
...
items
...
you
...
want
...
to
...
return,
...
and
...
the
...
MDX
...
expression
...
to
...
filter
...
with.
...
Here's
...
an
...
example:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
TopCount([Product].[Product].Members, 10.0, [Measures].[Sales])
ON ROWS
from [SteelWheelsSales]
|
For
...
people
...
coming
...
to
...
MDX
...
who
...
have
...
more
...
than
...
a
...
passing
...
knowledge
...
of
...
SQL,
...
it's
...
easy
...
to
...
get
...
confused
...
by
...
the
...
fact
...
that
...
you
...
need
...
to
...
filter
...
using
...
functions
...
in
...
this
...
way
...
and
...
not
...
using
...
the
...
WHERE
...
clause.
...
MDX
...
also
...
has
...
a
...
WHERE
...
clause
...
but
...
it
...
never
...
directly
...
filters
...
what
...
you
...
can
...
see
...
on
...
the
...
rows
...
and
...
columns
...
of
...
your
...
query
...
'
...
it
...
acts
...
more
...
as
...
a
...
third
...
axis,
...
one
...
member
...
thick,
...
which
...
slices
...
the
...
resultset.
...
Consider
...
the
...
following
...
query:
| Code Block |
|---|
select
{[Measures].[Sales]}
ON COLUMNS,
[Product].[Product].Members
ON ROWS
from [SteelWheelsSales]
|
It
...
has
...
no
...
WHERE
...
clause
...
and
...
it
...
doesn't
...
mention
...
the
...
Time
...
dimension
...
at
...
all,
...
but
...
that
...
doesn't
...
mean
...
we're
...
not
...
slicing
...
by
...
something
...
on
...
Time
...
'
...
we
...
are,
...
we're
...
seeing
...
values
...
for
...
the
...
All
...
member
...
on
...
Time.
...
When
...
we
...
introduce
...
a
...
WHERE
...
clause
...
we
...
can
...
explicitly
...
state
...
which
...
member
...
on
...
the
...
Time
...
dimension
...
we
...
want
...
to
...
see
...
values
...
for,
...
for
...
example
...
the
...
Year
...
2004:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
[Product].[Product].Members
ON ROWS
from [SteelWheelsSales]
where([Time].[All Years].[2004])
|
Notice
...
that
...
while
...
the
...
Products
...
that
...
appear
...
on
...
the
...
rows
...
haven't
...
changed,
...
the
...
values
...
for
...
Sales
...
have
...
'
...
we're
...
now
...
seeing
...
the
...
Sales
...
for
...
the
...
Year
...
2004
...
alone.
...
So
...
a
...
WHERE
...
clause
...
can't
...
directly
...
affect
...
which
...
members
...
appear
...
on
...
an
...
axis,
...
but
...
it
...
can
...
do
...
so
...
indirectly
...
if
...
you're
...
applying
...
some
...
kind
...
of
...
filter
...
to
...
that
...
axis.
...
If
...
we
...
go
...
back
...
to
...
our
...
Topcount()
...
example
...
and
...
add
...
a
...
WHERE
...
clause
...
specifying
...
that
...
we
...
see
...
values
...
for
...
2004
...
alone,
...
we'll
...
only
...
see
...
the
...
top
...
10
...
products
...
for
...
2004:
| Code Block |
|---|
select
{[Measures].[Sales]}
ON COLUMNS,
TopCount([Product].[Product].Members, 10.0, [Measures].[Sales])
ON ROWS
from [SteelWheelsSales]
where([Time].[All Years].[2004])
|
We
...
can
...
now
...
see
...
that
...
the
...
second-highest
...
ranking
...
product
...
is
...
the
...
2001
...
Ferrari
...
Enzo
...
and
...
not
...
the
...
1952
...
Alpine
...
Renault
...
'
...
the
...
Topcount
...
function
...
has
...
taken
...
into
...
account
...
the
...
WHERE
...
clause
...
in
...
its
...
filter.
...
In
...
fact
...
all
...
the
...
filter
...
functions
...
we've
...
looked
...
at
...
in
...
this
...
article
...
so
...
far
...
will
...
do
...
this
...
'
...
but
...
why
...
do
...
they
...
take
...
the
...
WHERE
...
clause
...
into
...
account
...
when
...
they
...
don't
...
take
...
what's
...
on
...
the
...
opposing
...
axis
...
into
...
account,
...
as
...
we
...
saw
...
earlier
...
with
...
the
...
Order
...
function
...
sorting
...
by
...
something
...
other
...
than
...
what
...
was
...
on
...
columns?
...
Simply
...
because
...
they
...
can:
...
the
...
WHERE
...
clause
...
is
...
an
...
axis
...
one
...
member
...
thick
...
so
...
logically
...
there's
...
no
...
problem
...
about
...
which
...
value
...
to
...
use
...
for
...
the
...
filtering
...
'
...
this
...
is
...
only
...
one
...
value
...
to
...
use,
...
the
...
value
...
that's
...
displayed.
...
On
...
the
...
other
...
axes
...
there
...
is
...
potentially
...
more
...
than
...
value
...
to
...
take
...
into
...
account
...
(for
...
example
...
on
...
the
...
rows
...
axis
...
there
...
could
...
be
...
more
...
than
...
one
...
column
...
to
...
choose
...
from)
...
so
...
MDX
...
instead
...
ignores
...
these
...
axes
...
and
...
makes
...
you
...
explicitly
...
state
...
what
...
you
...
want
...
to
...
filter
...
by.
...
As
...
with
...
SQL
...
there
...
is
...
the
...
concept
...
of
...
finding
...
the
...
union
...
of
...
two
...
sets
...
and
...
it's
...
also
...
possible
...
to
...
subtract
...
one
...
set
...
from
...
another
...
and
...
find
...
the
...
intersection
...
between
...
two
...
sets.
...
The
...
following
...
query
...
uses
...
the
...
Union()
...
function
...
to
...
return
...
all
...
Months
...
which
...
have
...
Sales
...
greater
...
than
...
500000
...
plus
...
those
...
which
...
have
...
Sales
...
less
...
than
...
200000:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
union( filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)<200000 ) ,
filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)>500000 ) )
ON ROWS
from [SteelWheelsSales]
|
The
...
Except()
...
function
...
takes
...
the
...
removes
...
all
...
members
...
found
...
in
...
one
...
set
...
from
...
another.
...
So,
...
for
...
example,
...
the
...
following
...
query
...
shows
...
all
...
Months
...
with
...
Sales
...
greater
...
than
...
200000
...
except
...
those
...
which
...
have
...
Sales
...
greater
...
than
...
500000:
| Code Block |
|---|
select
{[Measures].[Sales]}
ON COLUMNS,
except(
filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)>200000 ) ,
filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)>500000 ) )
ON ROWS
from [SteelWheelsSales]
|
The
...
Intersect()
...
function
...
returns
...
only
...
those
...
members
...
present
...
in
...
both
...
sets
...
passed
...
into
...
it,
...
so
...
for
...
example
...
the
...
following
...
query
...
returns
...
the
...
Months
...
which
...
have
...
Sales
...
greater
...
than
...
200000
...
and
...
Sales
...
less
...
than
...
500000:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
intersect(
filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)>200000 ) ,
filter( [Time].[Months].Members, ([Measures].[Sales],
[Time].Currentmember)<500000 ) )
ON ROWS
from [SteelWheelsSales]
|
Lastly,
...
it's
...
possible
...
to
...
iterate
...
over
...
every
...
member
...
of
...
a
...
set
...
and
...
perform
...
a
...
set
...
operation
...
at
...
each
...
iteration.
...
Why
...
would
...
you
...
need
...
to
...
do
...
this?
...
Let's
...
say
...
that
...
you've
...
found
...
our
...
top
...
3
...
selling
...
Products
...
and
...
you
...
want
...
to
...
find
...
the
...
top
...
5
...
Months
...
for
...
each
...
of
...
these
...
Products.
...
You
...
might
...
think
...
that
...
the
...
following
...
query
...
would
...
do
...
the
...
trick:
| Code Block |
|---|
select
{[Measures].[Sales]}
ON COLUMNS,
crossjoin( TopCount([Product].[Product].Members, 3, [Measures].[Sales]) ,
TopCount([Time].[Months].Members, 5, [Measures].[Sales]) )
ON ROWS
from [SteelWheelsSales]
|
However,
...
the
...
fact
...
that
...
the
...
top
...
5
...
Months
...
for
...
each
...
Product
...
are
...
the
...
same
...
might
...
make
...
you
...
suspicious
...
and
...
in
...
fact
...
further
...
investigation
...
will
...
show
...
that
...
this
...
query
...
does
...
not
...
return
...
what
...
we
...
wanted.
...
It
...
actually
...
returns
...
the
...
Crossjoin
...
of
...
the
...
top
...
3
...
Products
...
for
...
all
...
Months
...
and
...
the
...
top
...
5
...
Months
...
for
...
all
...
Products,
...
although
...
the
...
Sales
...
values
...
for
...
each
...
Product/Month
...
tuple
...
are
...
correct.
...
What
...
we
...
need
...
to
...
do
...
is
...
use
...
the
...
Generate()
...
function
...
to
...
iterate
...
through
...
the
...
set
...
of
...
Products
...
and
...
for
...
each
...
Product
...
return
...
the
...
top
...
5
...
Months
...
for
...
that
...
Product
...
as
...
follows:
| Code Block |
|---|
select {[Measures].[Sales]}
ON COLUMNS,
Generate( TopCount([Product].[Product].Members, 3, [Measures].[Sales]) ,
Crossjoin(
{[Product].Currentmember}
,
TopCount([Time].[Months].Members, 5, [Measures].[Sales]) ) )
ON ROWS
from [SteelWheelsSales]
|
In
...
this
...
case
...
Generate
...
is
...
being
...
passed
...
the
...
set
...
of
...
the
...
top
...
3
...
Products
...
as
...
its
...
first
...
parameter,
...
and
...
then
...
for
...
each
...
of
...
these
...
three
...
Products
...
it
...
Crossjoins
...
the
...
Currentmember
...
on
...
Product
...
(the
...
current
...
Product
...
in
...
the
...
iteration)
...
with
...
the
...
top
...
5
...
Months
...
which
...
produces
...
the
...
result
...
we're
...
looking
...
for.
...
Thanks
...
to
...
Chris
...
Webb
...
for
...
submitting
...
this
...
article
...
!