Power BI Divide two measure from different tables and show in a graph with time

Question

I have two tables, Table one has daily data, Table two has weekly data. I've created a start of week column in Table 1 to get weekly data. Data is as shown below:

I want to create a table where I can divide these two measures. Both measures are counts in a week. I want to present this in a line/bar chart with time at the x-axis. Right now when I use the Date of Table 1, My measure 2 takes the overall count as the date of table 2 is not present and vice versa. I was thinking of creating a new Calendar table but I'm unable to get these measure values in that table.

I tried creating a custom calendar table but I'm not getting the desired result. I'm getting correct values from table 2 but no values from table 1. I feel the problem is because table 1 has duplicate date values.

Table 1 actual data before consolidation:Measure is the count of case numbers

Answer 1

I think you need a slight paradigm shift in your thinking, potentially.

Rather than looking for a way to create a third table from two other tables, what you should do is create a relationship between the two tables to make a rational description of how you want these tables to work, and then write the DAX on top of it.

So, in your case, you describe one table having daily data, and the other having weekly. The intermediary calendar table would be a daily calendar, where each day (row) knows the end of week date.

You would then create a relationship from your daily table to the calendar table based on day, and create a second relationship to your weekly table based on end of week date. (assuming bi-directional filtering)

You could then create a measure:

myRatio = DIVIDE(SUM(DailyTable[value]), SUM(weeklyTable[value])

In your chart, you can then show the daily value as a fraction of the weekly value by using the 'Day' field from the calendar table, or you could show the ratio of the complete week from the daily table to the weekly total in the weekly table by using the end of week date in the chart.

If what you truly need is a 3rd table, then you could use the SUMMARIZE() function on this 3 table set to do the summarization into a 3rd table using the same principle.

myNewTable = 
SUMMARIZE(calendarTable
   ,calendarTable[End of Week Date]
   ,"My Ratio" //the name of the field you want to create
   ,[My Ratio] //the formula to describe what goes in the field
)