Use the Conditions tab to enter or revise an Access When
condition rule that can be expressed as a single Boolean expression, or the conjunction
(AND or OR) of one or more Boolean expressions.
Each node on the conditions tree defines a single comparison or other condition that
evaluates to True or False. The Access When condition rule
evaluates to True only if all nodes evaluate to true. While the order of
nodes may affect computational performance, order does not affect the outcome of the Access
When condition rule evaluation. Use these options: The conditions and logical operators
you enter on this tab also appear on the Advanced tab's
Condition array and Logic String field.
Procedure-
To create the first expression, perform the following actions:
-
Double-click the link below the When node.
-
The Condition dialog appears, and contains the default
condition, which compares two values.
-
Enter properties, literal constants, or function calls and parameters in the
fields, and select a relational operator.
- Optional:
Select the down arrow at the end of the row for a list of standard conditions
(derived from function alias rules). Open it by clicking the
Open icon.
If you select [expression evaluates to true], use the
Expression Builder for guided assistance.
- Optional:
Click OK to close the dialog and display the condition on
the tree.
-
To add, edit, or delete conditions, or to create groups of nested conditions:
- Open the Actions menu next to the node.
- Right-click the node.
You can use the following options:
- Edit
- Update the condition.
- Insert Condition
- Add a condition beneath the selected node. When you close the dialog, an
AND or OR logical operator appears to the left
of the new node. You can toggle between them by clicking the operator. Changing one
value changes all of them at the same node level.
- Insert Group
- Create a group of nested conditions. Enter a name in the Group
Label field to help identify the group on the tree. When you close the
dialog, the condition is indented beneath the node above it. Use the expand and
collapse icons to display or hide the nodes within the group. When collapsed, only
the label is displayed. To edit the label, select it on the tree and choose the
Edit menu option. You can nest groups at multiple levels;
for example: A AND B AND (C OR (E AND F)).
- Delete
- Delete the expression node. Node groups nested beneath it are also deleted.