Tuesday, January 31, 2006

How to create running totals in a query

How to create a running totals query in Microsoft Access

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Article ID:290136
Last Review:June 9, 2004
Revision:1.0
This article was previously published under Q290136
Advanced: Requires expert coding, interoperability, and multiuser skills.

This article applies only to a Microsoft Access database (.mdb).

For a Microsoft Access 2000 version of this article, see 208714 (http://support.microsoft.com/kb/208714/EN-US/).
For a Microsoft Access 97 version of this article, see 138911 (http://support.microsoft.com/kb/138911/).
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SUMMARYSUMMARY
MORE INFORMATIONMORE INFORMATION
Method 1Method 1
Method 2Method 2
REFERENCESREFERENCES
APPLIES TOAPPLIES TO

SUMMARY

This article demonstrates two methods that you can use to create a running totals query. A running totals query is a query in which the total for each record is a summation of that record and any previous records. This type of query is useful for displaying cumulative totals over a group of records (or over a period of time) in a graph or report.

Note You can see a demonstration of the technique that is used in this article in the sample file Qrysmp00.exe. For information about how to obtain this sample file, please see the following article in the Microsoft Knowledge Base:
207626 (http://support.microsoft.com/kb/207626/EN-US/) ACC2000: Access 2000 Sample Queries Available in Download Center
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MORE INFORMATION

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 1997. 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 select query and add the Orders table.
3.On the View menu, click Totals.
4.In the 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: 1997
  Show: No
The expression in the Field box filters the query's recordset to include data from 1997 only.
9.Run the query. Note that the RunTot field displays the following records with a running sum: 
   AYear    AMonth     RunTot       FDate
  --------------------------------------
  1997     1          2238.98      Jan
  1997     2          3840.43      Feb
  1997     3          5729.24      Mar
  1997     4          8668.34      Apr
  1997     5          12129.74     May
  1997     6          13982.39     Jun
  1997     7          17729.29     Jul
  1997     8          22204.73     Aug
  1997     9          26565.26     Sep
  1997     10         32031.38     Oct
  1997     11         36192.09     Nov
  1997     12         42748.64     Dec
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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
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REFERENCES

For more information about totals queries, click Microsoft Access Help on the Help menu, type calculations in the Office Assistant or the Answer Wizard, and then click Search to view the topics returned.
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APPLIES TO
•Microsoft Office Access 2003
•Microsoft Access 2002 Standard Edition
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Keywords:
kbhowto KB290136
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Source: http://support.microsoft.com/?kbid=290136
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