DAX for comparing text fields of snapshot data

[springje]

I have the following data set:

I am creating a matrix with Snapshot as the column, Attribute as the row, and I need a measure for using Value as the values. I am comparing the text of the Value column between the 2 snapshots, so I have a slicer for Snapshot that the user will select 2 snapshots.

I need the Total column to show "Changed" if the values are different, and "Same" or blank if the values are the same. I'm struggling with writing a measure to do this.

[Greg_Deckler]

Well, you are going to need an index or other "order" column so that you know what is before/after what, that should be a combination of your snapshot column and your attribute column. Then you are going to need to use EARLIER. See my article on Mean Time Between Failure (MTBF) which uses EARLIER: http://community.powerbi.com/t5/Community-Blog/Mean-Time-Between-Failure-MTBF-and-Power-BI/ba-p/3395...

[springje]

I'm not trying to compare everything in the table together, just the column values that are sliced to in the matrix. My data will be a monthly snapshot of the same dataset stored in the same table, and I want to look at an attribute and see whether it is the same, or different, in 2 selected snapshots.

I've been able to do this looking at dates as values and getting the difference between the dates, but I'm unsure how to do this with text values.

It is a fairly simple measure to do this with dates: https://community.powerbi.com/t5/Desktop/Compare-milestone-dates-of-snapshot-data-in-same-table/m-p/...

[springje · Accepted solution]

I was able to solve this one:

IF(HASONEVALUE(Data[Snapshot]),FIRSTNONBLANK(Data[Value],0),IF(EXACT(LASTNONBLANK(Data[Value],0),FIRSTNONBLANK(Data[Value],0)),"SAME","CHANGED"))