Unions in Tableau Desktop and join basics
In the following sections, you will learn the basics of unions, how to perform a union in Tableau, and learn the basics of joins. Unions will be focused on more as they are part of the examination, whereas joins are covered much more lightly.
Unions
Unions are added when you have two or more tables with the same fields or columns. All the user is doing is adding to the data (or appending it). In the real world, data can come in piecemeal, meaning that you get packets of data not already aligned to a table. In many instances, it is the Tableau developer’s responsibility to structure it well for visualization. Figure 6.22 will show how it works:
Figure 6.22: Union configuration
Figure 6.22 shows that Table 1 and Table 2 have the same fields (Date
, Sales State
, and Sales Amount
, with data in the same format. Although both tables contain three rows, the number of rows does not matter. What matters is that...