Database Reference
In-Depth Information
Figure 11.7. Revised settings for the Logical Elements category of the C
UST
C
OUNTY
field
Step 5: Determine What Actions Test the Rule
Theconstraintthebusinessruleimposesistestedwhenyouattempttoperformoneofthree
actions:
inserting
a record into the table or an entry into a field,
deleting
a record from the
table or a value within a field, or
updating
a field's value. Now that you've established a
business rule and understand the constraint it will impose, determine what actions test the
rule by identifying when a violation of the rule is most likely to occur. You can make this a
relatively easy task by asking yourself the following questions:
Will this rule be violated if I enter a new record into this table?
Will this rule be violated if I
do not
enter a new record into this table?
Will this rule be violated if I delete a record from this table?
Will this rule be violated if I enter a value into this field?
