Reputation: 1
How to get previous date member only among selected/visible members of date dimension?
I've tried PREVMEMBER and LAG functions but they return previous calendar date (yesterday).
Data in OLAP cube:
DATE | SUM
-----------------
2018-09-01 | 500
2018-09-02 | 150
2018-09-03 | 300
2018-09-04 | 777
2018-09-05 | 900
2018-09-06 | 1200
2018-09-07 | 1500
In my query I'm selecting different dates in a filter and I need to get SUM of previous visible date:
DATE | SUM | PREV_SUM
-------------------------------
2018-09-02 | 150 | NULL
2018-09-04 | 777 | 150 (from 2018-09-02)
2018-09-07 | 1500 | 777 (from 2018-09-04)
My MDX query:
WITH
MEMBER PREV_MEMBER AS
MEMBERTOSTR([dim_date].[Day Id].CURRENTMEMBER.PREVMEMBER)
MEMBER PREV_MEMBER_LAG AS
MEMBERTOSTR([dim_date].[Day Id].CURRENTMEMBER.lag(1))
MEMBER PREV_SUM AS
SUM(
STRTOMEMBER(PREV_MEMBER),
[Measures].[SUM]
)
SELECT
NON EMPTY {
[Measures].[SUM],
PREV_SUM,
PREV_MEMBER,
PREV_MEMBER_LAG
} ON COLUMNS,
NON EMPTY {(
[dim_date].[Day Id].ALLMEMBERS
)} ON ROWS
FROM (
SELECT ({
[dim_date].[Day Id].&[20180902],
[dim_date].[Day Id].&[20180904],
[dim_date].[Day Id].&[20180907]
}) ON COLUMNS
FROM [cub_main]
)
My result (returns yesterday):
DATE | SUM | PREV_SUM | PREV_MEMBER | PREV_MEMBER_LAG
--------------------------------------------------------------------------------------------
20180902 | 150 | 500 | [dim_date].[Day Id].&[20180901] | [dim_date].[Day Id].&[20180901]
20180904 | 777 | 300 | [dim_date].[Day Id].&[20180903] | [dim_date].[Day Id].&[20180903]
20180907 | 1500 | 1200 | [dim_date].[Day Id].&[20180906] | [dim_date].[Day Id].&[20180906]
How can I get PREV_SUM only among selected/displayed members?
Upvotes: 0
Views: 362
Reputation: 1
WITH
// Create custom set
SET SSS AS
{
[dim_date].[Day Id].&[20180902],
[dim_date].[Day Id].&[20180904],
[dim_date].[Day Id].&[20180907]
}
// Find current date member rank in custom set
// Decrement index of current member by 2
// Use ITEM function
MEMBER PREV_MEMBER AS
SETTOSTR(SSS.ITEM(RANK([dim_date].[Day Id].CURRENTMEMBER, SSS)-2))
MEMBER PREV_SUM AS
SUM(
STRTOSET(PREV_MEMBER),
[Measures].[SUM]
)
SELECT
NON EMPTY {
[Measures].[SUM],
PREV_MEMBER,
PREV_SUM
} ON COLUMNS,
NON EMPTY {(
// Use custom set in rows as a date filter
SSS
)} ON ROWS
FROM [cub_main]
Upvotes: 0
Reputation: 35557
Try creating a custom set in your WITH clause. The set will be made up of the dates.
Then use the GENERATE function to iterate over the set. I think lag should then use only the dates in the set.
(Apologies I am away from a PC so unable to test)
Upvotes: 0