SUMMARIZE AND SUMMARIZECOLUMNS in Power BI

Today we are going to see SUMMARIZE, ADDCOLUMNS and SUMMARIZECOLUMNS:

Extension columns are columns that you add to existing tables. You can obtain extension columns by 

using both ADDCOLUMNS and SUMMARIZE. Basically these functions adds columns / tables over the conditions applied.

For example, the following query adds a Year Production column to the rows returned from the Product table.

EVALUATE

ADDCOLUMNS(

    Product,

    "Year Production", YEAR( Product[Product Start Date] )

)

In below query, you can count the number of products for each product category by using the following query

EVALUATE

SUMMARIZE(

    Product,

    Product[Product Category Name],

    "Products", COUNTROWS( Product )

)

For performance reasons it is better to add ADDCOLUMNS() outside. 

EVALUATE

ADDCOLUMNS(

    SUMMARIZE(

        Product,

        Product[Product Name],

        Product[Product Start Date]

    ),

    "Year Production", YEAR( Product[Product Start Date] )

)

SUMMARIZECOLUMNS: Returns a summary table over a set of groups.

Below query returns the sumofsales for calendar year and category name

Summarize =

SUMMARIZECOLUMNS(

    'Calendar'[Year],

    Categories[CategoryName],

    "sumofsales", [Sales])

Thanks, :)