Sum Function

Description

Returns the sum of a set of values contained in a specified field on a query.

Syntax

Sum(expr)

The expr placeholder represents a string expression identifying the field that contains the numeric data you want to add or an expression that performs a calculation using the data in that field. Operands in expr can include the name of a table field, a constant, or a function (which can be either intrinsic or user-defined but not one of the other SQL aggregate functions).

Remarks

The Sum function totals the values in a field. For example, you could use the Sum function to determine the total cost of freight charges.

The Sum function ignores records that contain Null fields. The following example shows how you can calculate the sum of the products of UnitPrice and Quantity fields:

SELECT
Sum(UnitPrice * Quantity)
AS [Total Revenue] FROM [Order Details];

You can use the Sum function in a query expression. You can also use this expression in the SQL property of a QueryDef object or when creating a Recordset based on an SQL query.

See Also Count function, QueryDef object ("DAO Language Reference"), SELECT statement, SQL property ("DAO Language Reference").

Specifics (Microsoft Access)

In Microsoft Access, you can use the Sum function in the query design grid, in an SQL statement in SQL view of the Query window, or in an SQL statement within Visual Basic code. You can also use the Sum function in a calculated control on a form or report.

The Sum function is most useful in totals queries and crosstab queries. It functions the same way whether you create the query in the query design grid or as an SQL statement in SQL view.

In the query design grid, you can create a new totals query by clicking the Totals button on the Query Design toolbar. The Total row is then inserted in the grid. You can set the Total cell beneath a field to the aggregate function to perform on the data in that field.

For example, suppose you have an Orders table that has both a Freight field and a ShipCity field. You can create a query that displays the sum of freight costs for orders sent to each city. Create a new totals query, and drag the ShipCity field to the query design grid. The Total cell beneath the ShipCity field should be set to Group By. Drag the Freight field to the query design grid, and set the Total cell beneath it to Sum. When you run the query, it will display the sum of freight costs by city.

You can view the SQL statement for this query by switching to SQL view. In this example, Microsoft Access creates the following SQL statement:

SELECT ShipCity, Sum(Freight) AS SumOfFreight
FROM Orders GROUP BY ShipCity;

You can also use an SQL statement within Visual Basic code. For example, the following code creates a dynaset-type Recordset object from the preceding SQL statement:

Sub SumFreight()
    Dim dbs As Database, rst As Recordset, strSQL As String

    Set dbs = CurrentDb
    strSQL = "SELECT ShipCity, Sum(Freight) AS SumOfFreight " _
    & "FROM Orders GROUP BY ShipCity;"
    Set rst = dbs.OpenRecordset(strSQL)
    rst.MoveLast
    Debug.Print rst.RecordCount
    Set dbs = Nothing
End Sub

To use the Sum function in a calculated control, set the control's ControlSource property to an expression containing the Sum function. For example, to display the sum of freight costs for a set of orders in a text box, enter the following expression in the ControlSource property of the text box:

=Sum([Freight])

If you use the Sum function in a calculated control, you can restrict the set of records against which the function is performed by setting the form's Filter property.

Example

This example uses the Orders table to calculate the total sales for orders shipped to the United Kingdom.

This example calls the EnumFields procedure, which you can find in the SELECT statement example.

Sub SumX()

    Dim dbs As Database, rst As Recordset

    ' Modify this line to include the path to Northwind
    ' on your computer.
    Set dbs = OpenDatabase("Northwind.mdb")

    ' Calculate the total sales for orders shipped to
    ' the United Kingdom.  
    Set rst = dbs.OpenRecordset("SELECT" _
        & " Sum(UnitPrice*Quantity)" _
        & " AS [Total UK Sales] FROM Orders" _
        & " INNER JOIN [Order Details] ON" _
        & " Orders.OrderID = [Order Details].OrderID" _
        & " WHERE (ShipCountry = 'UK');")

    ' Populate the Recordset.
    rst.MoveLast

    ' Call EnumFields to print the contents of the 
    ' Recordset. Pass the Recordset object and desired
    ' field width.
    EnumFields rst, 15
    
    dbs.Close

End Sub

Example (Microsoft Access)

The following example assumes that you have an Orders table that contains fields called OrderID and ShipCountry, and an Order Details table that contain fields called UnitPrice and Quantity. You can use the Sum function to calculate the total sales for orders shipped to the United Kingdom. Enter the following expression in SQL view in the Query window:

SELECT Sum([UnitPrice]*[Quantity]) AS [TotalUKSales]
FROM Orders INNER JOIN [Order Details]
ON Orders.[OrderID] = [Order Details].[OrderID]
WHERE ([ShipCountry] = 'UK');

The next example creates a calculated control that displays the total sales for records in the Order Details table. Open a new form and set its RecordSource property to Order Details. Enter the following expression in the ControlSource property of a text box on the form. To apply a condition that limits the search to only some records, such as those for orders shipped to the United Kingdom, set the form's Filter property.

=Sum([UnitPrice]*[Quantity])