Because the tag data we want to use for our bar chart is stored in a different file, we need to know how to work with multiple data sources.
- Connect to multiple data sources.
- Join datasets.
There are three ways to connect to a new data source.
Whichever method we choose, we will receive the same connect options we did at the beginning of the tutorial. As we did then, choose Text file and navigate to the data folder downloaded from GitHub. This time, choose tags.csv. Tableau will open up the data from tags.csv as it did when we connected to mods.csv. Many of the columns are the same as what we have seen before, but there is now a column for Tag. There are also many instances of the same mod. For example, the mod with ID 11 has multiple rows, once for each tag associated with the mod.
Instead of going on to a new worksheet, however, this time we need to do one more step. If we only use the data from this file, while we can make a bar chart of tags, it will be disconnected from the rest of the data. Instead, we will join our two datasets. This will allow us additional filter functionality later on.
The overlapping circles that connect tags.csv and mods.csv indicate the type of join we are using. By default only the space between them is shaded in, meaning we are doing an inner join. An inner join would consist of only records that have matching values in both datasets.