Ever had a column of numeric data that you wanted to dynamically display the sum. By using a simple variation I came up with, the DBLookUp formula used with the @Sum command is very powerful. This formula lookup numeric data based on a key field. That data is then summed by the @Sum formula and stored to a variable which is error checked before being displayed.
Total := @Sum(@DbLookup("" : "NoCache"; Server : Database ; View; Key; Column Number or Field Name to return ));
@If(@IsError(Total); "Error!" ; Total)