➕ Sum or Max of Multiple Columns

Configurable Joins makes it easy to use the aggregate SQL functions like SUM() or MAX(). However, these operate across rows - what you want the max or sum of several columns on the same row? 🚣‍♀️

Sum

Using a table value constructor allows for summing up all non-null values from a set. Replace @valueX with your whatever exports you desire.

(SELECT SUM(v)
FROM (
    VALUES (@value1)
        ,(@value2)
    ) AS t(v))

Occasionally, you may encounter datatype errors when all values are NULL and have datatypes incompatible with SUM(). Adding the following extra “value” should prevent this.
,(cast(NULL AS INT)) /* Prevent datatype error */

Max

Similarly, a table value constructor can also return the maximum non-null value from a set:

(SELECT MAX(v)
FROM (
    VALUES (@value1)
        ,(@value2)
    ) AS t(v))

However, there’s an easier way as of SQL Server 2022: the GREATEST() function! It does essentially the same thing with less fuss.

GREATEST(@value1, @value2)