ALLEXCEPT

The ALLEXCEPT function is useful for performing a calculation that affects all rows in a table regardless of the context of the calculation. It is usually used as an intermediate function in a calculation (usually as an argument in a CALCULATE function) to modify the set of rows on which it is to be performed. In practice -used as an argument in a CALCULATE function- it removes the filter from the context for all columns except those included as arguments.

One case in which its use is very useful is when we want to apply the ALL function to most of the columns of a table. In this case, it will be easier to use the ALLEXCEPT function to indicate the columns to which you do not want to apply the functionality offered by ALL instead of using the ALL function directly and having to add as arguments all the columns to which the functionality is to be applied.

It should be noted that if a new column is added to the table later, the function will also apply to it unless it is explicitly added to the argument list.