The Table Constraints Page: Table

The Constraints page is used to set a list of constraints for table fields. Constraints are used to control data stored in the table automatically. For example, the sum of cache money cannot be negative or loan issue date must be later than the date of bank foundation.

To create a new constraint:

In the web application click the Add button. A new string is added to the list of constraints.
In the desktop application:

Click the Add button.
Double-click the empty space of the list of constraints.

The Constraint Properties dialog box opens:

All boxes are set to default values.

Set constraint attributes:

Name. Enter constraint name. The default name is Constraint.
Identifier. Enter constraint’s unique identifier (only Latin letters, numbers and underscores can be used, spaces are not allowed). The default identifier: <Table identifier>_CHECK<Number>.
Table Fields. The area cannot be edited. It includes the table fields with constraints to be imposed on. It is available only in the desktop application.
Expression/Constraint Text. Create the expression, by which constraints are imposed on the selected data. The expression should return logical value (True or False), the expression is created by means of table fields, arithmetic, logical, unary operations, relation operations, as well as built-in SQL functions.

To change displayed properties in the web application, select or deselect the required properties in the drop-down menu of the Settings button.

To edit the selected constraint:

In the web application set or change the required constraint settings in corresponding columns.
In the desktop application click the Edit button or double-click the constraint in the list. The Constraint Properties dialog box opens.

To delete the selected constraint:

In the web application click the Delete button.
In the desktop application click the Delete button or press CTRL+DELETE.

A confirmation dialog box opens.