Returns the sum of an expression evaluated for each row in a table.
The SUMX function takes as its first argument a table, or an expression that returns a table. The second argument is a column that contains the numbers you want to sum, or an expression that evaluates to a column.
Only the numbers in the column are counted. Blanks, logical values, and text are ignored.
The following example first filters the table, InternetSales, on the expression, ShippingTerritoryID = 5, and then returns the sum of all values in the column, Freight. In other words, the expression returns the sum of freight charges for only the specified sales area.
If you do not need to filter the column, use the SUM function. The SUM function is similar to the Excel function of the same name, except that it takes a column as a reference.