DSUM returns the total of the values that meet the specified criteria.
The DSUM function operates much as the sum function except that it operates on a database with criteria. The database is the cell reference range or named range of the database, and the field is referenced as the column number from left to right. The criteria is a range that is referenced, and the function operates from the parameters set. The field can also be a cell reference. The criteria enable you to apply constraints, as shown in the example in Figure 3.7. Notice the criteria applies the sum of all sales for the cars greater than 1995 and less than 2000. The sum of sales dollars from 1996 through 1999 equals $2,034,572.
Figure 3.7 The DSUM function sums up all numbers that fall within the specified criteria, in this case, it sums up all car sales greater than 1995 and less than 2000 (after the year 1995).