Combining Columns Using Set Operations
After you have selected a subject area for an analysis, you can combine columns from one or more subject areas using Set operations such as Union or Intersect. By combining columns, you create a new column for displaying the data in a different way.
Guidelines for Selecting Columns to Combine
When selecting columns to combine, keep the following guidelines in mind:
The number and data types of the columns to combine must be the same. The number of rows that are returned for each column can differ.
You can select columns from the same subject area or from a different subject area, but the columns must have some commonality.
You can specify one Set operation for one collection of criteria. For example, if you create criteria from the A-Sample Sales subject area, you can apply only one Set operation to those columns. You cannot apply different Set operations to different columns in the collection of criteria.
You cannot use hierarchical columns, selection steps, or groups when you combine criteria.
Difference Between Combining Columns Using Set Operations and Adding Columns from Related Subject Areas
Combining columns using Set operations produces different results than adding columns from related subject areas:
When you combine columns using Set operations, the analysis results show a single newly combined column governed by a Set operation. For example, see "Combining Columns from One or More Subject Areas".
When you add columns from related subject areas to an analysis, the results show each added column individually. For example, if you have the appropriate permissions, then you can create an analysis by selecting one column from a primary subject area and selecting another column from a related subject area.
For information, see "What Are Subject Areas and Columns?"
Combining Columns from One Subject Area
The A-Sample Sales subject area contains the Offices folder, which contains the D1 Office and D2 Department columns. You can combine these two columns and create a new column called Offices & Departments. You can include the Union All Set operation to specify that this new column shows all the values from both columns in a single column in a table.