Tableau: How to calculate number of days

0
votes

I have custom SQL query in tableau that displays the data in the following format:

   Start Date |  App 
    6/21/16    app1
    6/22/16    app2
    6/23/16    app3

In this case, the end date would be '6/23/16'. So, app1 has been "live" for 2 days, app2 for 1 and so on.

I am trying to find the the number of days an app has been live. I can try using the DateDiff function but I would need to hardcode the values in that case and I want it to be dynamic.

The challenge is to have a calculated field that would find the max date in the entire column and subtract it from the individual app's date. This would give me the 'number of live days' for an app.

I am new to tableau and do not know how to proceed. Any help is appreciated.

2
tableau-api

2 Answers

3
votes

Here is one solution.

datediff('day', [Start Date], { fixed : max([Start Date]) } )

Note the expression in Curley braces. That is a level of Detail (LOD) calculation -- basically a separate subquery at a potential different level of detail. So you can compare values for each row with values computed based on the whole table.

Depending on how and where you want to use this calculation, you might want to alter that LOD calculation to be fixed for certain dimensions or include or exclude certain dimensions. The online help should explain.

0
votes

Just use"DATEDIFF('day',[Order Date], [Ship Date])", order date and ship date are example dimensions from superstore data.xlxs