I'm using Tableau Desktop 10.4.6 32-bit, and I've just taken my first classes on using it. I have to create discrepancy reports for data residing in two databases. I have to check for primary key matches between the two, and mismatches on both databases. In my tiny example, I have two initial data sources called OldPoles and NewPoles, with ID keys in both, and for this example only one ID matches between them. The OldPoles data source has an addtional field called Area that represents just 3 of the 4 compass points.
I use Tableau then to create an inner join between the OldPoles and NewPoles data sources, calling it OldPoles IN NewPoles. I then create two distinct left joins: one for OldPoles NOT IN NewPoles, and a NewPoles NOT in OldPoles data source, with the latter data source not critical for my immediate need. The joins are built with associated filters to produce the correct data.
Next, I want to create a Viz that shows the breakout of Old Poles, OldPoles IN NewPoles, and OldPoles NOT IN NewPoles. I set my column to OldPoles.Area and my row to OldPoles.CNT(Number of Records), so I'm creating a bar chart reflecting the 3 areas and their counts. I then want to create a dual axis, so I first drag the OldPoles IN NewPoles.CNT(Number of Records) to the right of the view, triggering a double line and then drop. I change my view from the generated circles back to the bar, right-click on Synchronize Axis and get the updated chart which appears to be a stacked bar.
Now I want to drag the OldPoles NOT IN NewPoles to show all three measures. I am once again dragging and dropping, but this time it's the OldPoles NOT IN NewPoles.CNT(Number of Records) measure, acquire the double line and drop. The bar charts appear the way I want them to be. I am able to change the alias of each measure name to match the data source name with no trouble. But that's when the problems start. I can't Synchronize Axis for the last data source, although it is based on the same Number of Records measure as the other two prior data sources.
I also want to make sure that the tooltips reflect the right category. But I am unable to access tool tips for all 3 data sources, I only can edit tooltips for two of them, and it appears that the last two data sources have been consolidated into Measure Values for the same tooltip. So, if I edit the tooltip for the OldPoles in NewPoles data source, the tooltip also applies to the OldPoles NOT in NewPoles data source. However, the counts for each data source appear to come out correctly when I hover over them with the tooltip.
I also can't Synchronize Axis for the last data source, although it is based on the same Number of Records measure as the other two prior data sources.
The only thing that I believe that I may be doing wrong is assuming that the Dual Axis functionality can be extended to more than two measures. Otherwise, I am stuck. Also, if there a way to append the NewPoles NOT IN OldPoles data source as a count for Area NULL within the same graph, that would be great. But I might already be asking too much for the Viz to do. If the Tableau joins are the cause of this, then I will need to pre-join data in a database and produce another table or extract to simplify Tableau front-end work. Please advise me! Thanks!