QoQ changes by Customer in DAX - powerbi

Question

I would like to create a DAX formula to calculate the increases and decreases of customers across periods. Following is a sample of the data that I have
Year-Quarter|Customer|Credit-Limit
2019Q2|A|50
2019Q2|B|100
2019Q2|C|100
2019Q2|D|200
2019Q2|E|1000
2019Q2|F|200
2019Q3|A|50
2019Q3|B|200
2019Q3|C|100
2019Q3|D|50
2019Q3|E|500
2019Q3|F|300
I am looking to create a summary by Year-Quarter showing the number of customers that had an increase/decrease/none of their Credit-Limit.
Note that this is just a sample and the actual data is >10M rows. So even though I can create another table, I think from a computation standpoint, a measure would be more useful
Desired Output:
A commentary like the following: "There are 2 customers that have increased credit limit in 2019Q3"
Done so far:
Prev Quarter Credit Limit =
VAR CurrentYearQuarter = MAX(Sheet1[Year-Quarter])
VAR Quarter_Year =
LEFT (CurrentYearQuarter, 4)
VAR Quarter_period =
RIGHT (CurrentYearQuarter, 1 )
RETURN
IF (
Quarter_period = "1",
CALCULATE (
SUM ( Sheet1[Credit Limit] ),
Sheet1[Year-Quarter]
= ( Quarter_Year - 1 )
& "Q"
& ( Quarter_period + 3 )
),
CALCULATE (
SUM ( Sheet1[Credit Limit] ),
Sheet1[Year-Quarter]
= Quarter_Year
& "Q"
& Quarter_period - 1
)
)
Inc/Dec = IF(SUM(Sheet1[Credit Limit]) - [Prev Quarter Credit Limit] > 0,"Inc",
IF(SUM(Sheet1[Credit Limit]) - [Prev Quarter Credit Limit] < 0,"Dec","None"))
Commentary = "There are " &
CALCULATE(DISTINCTCOUNT(Sheet1[Customer]),
FILTER(Sheet1, [Inc/Dec] = "Inc" && Sheet1[Year-Quarter] = "2019Q3"))
Current output:
Commentary: "There are 4"
I am not sure why I am getting 4 as compared to 2 as the number here. Help or guidance would be really appreciated

Answer 1

I've slightly altered the input data for experimental purpose, I've added
2018Q3 | A | 200
2018Q4 | A | 50
2019Q1 | A | 50
I've added a Quarter-Calendar (which is a calculated table using VALUES(Sheet1[Year-Quarter])
Then by adding more columns to this new table, extracting the current year and quarter using LEFT and RIGHT, then calculating the previous quarter, previous year and combining to a Prevoius-Year-Quarter column:
]
Using this Q-Calendar I create a 1:* relationship to the Sheet1 table between [Year-Quarter] and [Year-Quarter], then I create a second inactive 1:* relationship between [Previous-Year-Quarter] and [Year-Quarter] like this:
I then create two measures, one for sum of previous quarter credit an one for current quarter credit:
Current-Quater CL =
var currentQ = MAX('Q-Calendar'[Year-Quarter])
var tempTable =
FILTER(
ALL('Q-Calendar');
'Q-Calendar'[Year-Quarter] = currentQ
)
return
CALCULATE(
SUM('Sheet1'[Credit-Limit ]);
tempTable
)
In the [Previous-Quarter CL] measure I use USERELATIONSHIP to activate the passive relationship I added from the Q-Calendar.
Prev-Quater CL =
var currentQ = MAX('Q-Calendar'[Year-Quarter])
var tempTable =
FILTER(
ALL('Q-Calendar');
'Q-Calendar'[Year-Quarter] = currentQ
)
return
CALCULATE(
SUM('Sheet1'[Credit-Limit ]);
tempTable;
USERELATIONSHIP('Sheet1'[Year-Quarter]; 'Q-Calendar'[Previous-Year-Quarter])
)
Then create the Inc/Dec measure like this:
Increase/Decrease =
var temp = [Current-Quater CL]-[Prev-Quater CL]
return
SWITCH(
TRUE();
temp > 0; "Increase";
temp < 0; "Decrease";
"No change"
)
And finally created a new (actually 3 new) Commentary measures like this:
Commentary_2 = "There are " &
var customers = VALUES(Sheet1[Customer])
return
SUMX(
customers;
CALCULATE(
IF(
[Current-Quater CL]-[Prev-Quater CL] > 0;
1;
0
)
)
)&" customers how have increased their credit"
Using the Year-Quarter column from the Q-calendar as a slicer I get the current status and I can select a previous quarter to see the status at that time:
N.B: The code in my measures can be optimised, I just kept them as detailed as this to make it more understandable.