ACC: How to Create Running Totals in a Query (95/97)

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Method 1

The first method uses a DSum() function and criteria in a query to create a running sum over time. The DSum() function sums the current record and any previous records. When the query moves to the next record, the DSum() function runs again and updates the cumulative total.

The following sample query uses the Orders table from the sample database Northwind.mdb to create a running sum of the freight costs for each month in 1994. The sample data is limited to one year for performance reasons. Because the DSum() function runs once for every record in the query, it may take several seconds (depending on the speed of your computer) for the query to finish processing. To create and run this query, follow these steps:

1. Open the sample database Northwind.mdb.
2. Create a new query and add the Orders table.
3. On the View menu, click Totals.
4. In first column of the query design grid, type the following expression in the Field box, and make the following selections for the Total, Sort, and Show boxes:
   

   Field: AYear: DatePart("yyyy",[OrderDate]) Total: Group By Sort: Ascending Show: Yes

   
   The expression in the Field box displays and sorts the year portion of the OrderDate field.
5. In the second column of the query design grid, type the following expression in the Field box, and make the following selections for the Total, Sort, and Show boxes:
   

   Field: AMonth: DatePart("m",[OrderDate]) Total: Group By Sort: Ascending Show: Yes

   
   The expression in the Field box sorts and displays the month portion of the Order Date field as an integer value from 1 to 12.
6. In the third column of the query design grid, type the following expression in the Field box, and make the following selections for the Total and Show boxes. NOTE: In the following example, an underscore (_) at the end of a line is used as a line-continuation character. Remove the underscore from the end of the line when re-creating this example.
   

   Field: RunTot: DSum("Freight","Orders","DatePart('m', _ [OrderDate])<=" & [AMonth] & " And DatePart('yyyy', _ [OrderDate])<=" & [AYear] & "") Total: Expression Show: Yes

   
   The expression in the Field box uses the DSum() function to sum the Freight field when the values in both the AMonth and the AYear fields are less than or equal to the current record that the query is processing.
7. In the fourth column of the query design grid, type the following expression in the Field box, and make the following selections for the Total, Sort, and Show boxes:
   

   Field: FDate: Format([OrderDate],"mmm") Total: Group By Sort: Ascending Show: Yes

   
   The expression in the Field box displays each month in a textual format, such a Jan, Feb, Mar, and so on.
8. In the fifth column of the query design grid, type the following expression in the Field box, and make the following selections for the Total, Criteria, and Show boxes:
   

   Field: DatePart("yyyy",[OrderDate]) Total: Where Criteria: 1994 Show: No

   
   The expression in the Field box filters the query's recordset to include only data from 1994.
9. Run the query.

In Microsoft Access 97, note that the RunTot field displays the following records with a running sum:

     Ayear     Amonth     RunTot     Fdate
     -------------------------------------
     1994      8           1288.18   Aug
     1994      9           2685.35   Sep
     1994      10          3808.83   Oct
     1994      11          5219.05   Nov
     1994      12          7481.28   Dec
				

In Microsoft Access version 7.0, note that the RunTot field displays the following records with a running sum:

     Ayear     Amonth     RunTot     Fdate
     -------------------------------------
     1994      1          1936.65    Jan
     1994      2          3452.52    Feb
     1994      3          5479.33    Mar
     1994      4          8607.74    Apr
     1994      5          12094.67   May
     1994      6          13859.39   Jun
     1994      7          17729      Jul
     1994      8          21992.58   Aug
     1994      9          27477.79   Sep
     1994      10         31767.05   Oct
     1994      11         36681.15   Nov
     1994      12         42894.37   Dec
				

Method 2

The second method uses a totals query with a DSum() function to create a running total over a group.

The following sample query uses the Orders table to sum freight costs per employee as well as to calculate a running sum of the freight. To create and run the query, follow these steps:

1. Open the sample database Northwind.mdb.
2. Create a new select query and add the Orders table.
3. On the View menu, click Totals.
4. In the first column of the query design grid, add the following field to the Field box, and make the following selections for the Total and Show boxes:
   

   Field: EmpAlias: EmployeeID Total: Group By Show: Yes

   
   This field groups data by EmployeeID.
5. In the second column of the query design grid, add the following field to the Field box, and make the following selections for the Total and Show boxes:
   

   Field: Freight Total: Sum Show: Yes

   
   This field sums the freight data.
6. In the third column of the query design grid, type the following expression in the Field box, and make the following selections for the Total and Show boxes. NOTE: In the following example, an underscore (_) at the end of a line is used as a line-continuation character. Remove the underscore from the end of the line when re-creating this example.
   

   Field: RunTot: Format(DSum("Freight","Orders","[EmployeeID]<=" _ & [EmpAlias] & ""),"$0,000.00") Total: Expression Show: Yes

   
   The expression in the Field box uses a DSum() function to sum the Freight field when the EmployeeID is less than or equal to the current EmpAlias, and then formats the field in dollars.
7. Run the query. Note that the RunTot field displays the following records with a running sum:
   

        Employee            SumOfFreight   RunTot
        ---------------------------------------------
        Davolio, Nancy      $8,836.64      $8,836.64
        Fuller, Andrew      $8,696.41      $17,533.05
        Leverling,Janet     $10,884.74     $28,417.79
        Peacock, Margaret   $11,346.14     $39,763.93
        Buchanan, Steven    $3,918.71      $43,682.64
        Suyama, Michael     $3,780.47      $47,463.11
        King, Robert        $6,665.44      $54,128.55
        Callahan, Laura     $7,487.88      $61,616.43
        Dodsworth, Anne     $3,326.26      $64,942.69