Microsoft Office Tutorials and References
In Depth Information
Access Chapter 3 Maintaining a Database
If a required ﬁ eld contains no data, Access indicates this by displaying an error
message as soon as you attempt to leave the record (Figure 3–43). The ﬁ eld must contain
a valid entry before Access will move to a different record.
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Access dialog box
When entering data into a ﬁ eld with a validation rule, you may ﬁ nd that Access
displays the error message and you are unable to make the necessary correction. It may be
that you cannot remember the validation rule you created or it was created incorrectly. In
such a case, you neither can leave the ﬁ eld nor close the table because you have entered
data into a ﬁ eld that violates the validation rule.
If this happens, ﬁ rst try again to type an acceptable entry. If this does not work,
repeatedly press the BACKSPACE key to erase the contents of the ﬁ eld and then try to leave
the ﬁ eld. If you are unsuccessful using this procedure, press the ESC key until the record is
removed from the screen. The record will not be added to the database.
Should the need arise to take this drastic action, you probably have a faulty
validation rule. Use the techniques of the previous sections to correct the existing validation
rules for the ﬁ eld.
To Use a Lookup Field
Earlier, you changed all the entries in the Client Type ﬁ eld to MED. Thus, you have created a rule that will
ensure that only legitimate values (MED, DNT, or LAB) can be entered in the ﬁ eld. You also made Client Type
a Lookup ﬁ eld using a mass change. You can make changes to a Lookup ﬁ eld by clicking the ﬁ eld to be changed,
clicking the arrow that appears in the ﬁ eld, and then selecting the desired value from the list.
The following steps change the Client Type value on the third record to DNT and on the ninth record to LAB.
• Open the Client table in Datasheet
view and ensure the Navigation pane
• Click in the Client Type ﬁ eld on the
third record to display the arrow
value to be