Returns the union of the tables whose columns match.
A table that will participate in the union.
A table that contains all the rows from each of the table expressions.
The tables must have the same number of columns.
Columns are combined by position in their respective tables.
The column names in the return table will match the column names in the first Table.
Duplicate rows are retained.
The returned table has lineage where possible. For example, if the first column of each Table has lineage to the same base column C1 in the model, the first column in the UNION result will have lineage to C1. However, if combined columns have lineage to different base columns, or if there is an extension column, the resulting column in UNION will have no lineage.
When data types differ, the resulting data type is determined based on the rules for data type coercion.
The returned table will not contain columns from related tables. Therefore, when the result corresponds to a base table, once applied to the filter context it does not involve the expanded table and it only filters columns of he base table.
Learn more about UNION in the following articles:
Transition Matrix Using Calculated Tables
In the 2015 September update, Power BI introduced calculated tables, which are computed using DAX expressions instead of being loaded from a data source. This article shows the usage of calculated tables to solve the pattern of transition matrix for… » Read more
Creating a slicer that filters multiple columns in Power BI
This article describes how to create a slicer showing the values of multiple columns, applying the filter on any of the underlying columns. » Read more
Showing the top 5 products and Other row
This article shows how to add an additional “other” row to the selection obtained using the Top N filter in a Power BI report. » Read more
Other related functions are:
Contributors: Alberto Ferrari, Marco Russo
MSDN documentation: https://docs.microsoft.com/en-us/dax/union-function-dax