Microsoft Office

Using Data Validation 25
FIGURE 25.4
This drop-down list was created using data validation.
TIP
If you specify a range for a list, the range must be on the same sheet. If your list is in a range
on a different worksheet, you can provide a name for the range and then use the name as your
list source (preceded by an equal sign). For example, if the list is on a different sheet in a range named
MyList, enter the following:
=MyList
Using Formulas for Data Validation Rules
For simple data validation, the data validation feature is quite straightforward and easy to use. But the real
power of this feature becomes apparent when you use data validation formulas.
The formula that you specify must be a logical formula that returns either True or False.
If the formula evaluates to True, the data is considered valid and remains in the cell. If the
formula evaluates to False, a message box appears that displays the message specified in the Error Alert tab
of the Data Validation dialog box.
NOTE
You can specify a formula in the Data Validation dialog box by selecting the Custom option in the Allow
drop-down list of the Settings tab. You can enter the formula directly into the Formula control, or you can
enter a reference to a cell that contains a formula. The Formula control appears in the Setting tab of the
Data Validation dialog box when the Custom option is selected.
Understanding Cell References
If the formula that you enter into the Data Validation dialog box contains a cell reference, that reference is
considered a relative reference, based on the upper-left cell in the selected range.
The following example clarifies this concept. Suppose that you want to allow only an odd number to be
entered into the range B2:B10. None of Excel’s Data Validation rules can limit entry to odd numbers, so a
formula is required.
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