ACC2000: Adding the Values of Fields Returns a Blank Result If Some of the Fields Contain Null Values (308631)
The information in this article applies to:
This article was previously published under Q308631 Novice: Requires knowledge of the user interface on single-user computers.
This article applies to a Microsoft Access database (.mdb) and to a Microsoft Access project (.adp).
SYMPTOMS
When you try to add the values of two fields in a database, and one of the fields contains null values in a few records, the result of the calculation for those records appears blank (null).
CAUSE
This behavior occurs because the result of a calculation that involves a null value is also null. A null value is not the same as a value of zero (0); instead, think of a null value as an unknown value. Adding an unknown value to a number yields an unknown result.
RESOLUTION
To work around this behavior, create an expression that uses the Nz() function to convert null values to zeros, for example, (Nz([Field1])+Nz([Field2]))
MORE INFORMATION
For more information about handling null values, either search the Access Help index for "blank fields, null values", or ask the Access 2000 Office Assistant.
| Modification Type: | Major | Last Reviewed: | 6/29/2004 |
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| Keywords: | kbprb kbProgramming KB308631 |
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