| Form Designer usage / Properties list | |
The required property forces the user to modify the content of a field during an INPUT or INPUT ARRAY statement.
This property forces the user to modify the content of the field during the dialog execution. If the user subsequently erases the entry during the same input, the runtime system considers the required property satisfied.
The required property is effective only when the field name appears in the list of screen fields of an INPUT or INPUT ARRAY statement.
If a default property is used for the field and the input dialog does not use the WITHOUT DEFAULTS option, the runtime system assumes that the default value satisfies the required property.
If both the required and default properties are assigned to the same field, the runtime system assumes that the default value satisfies the required property.
If the dialog instruction uses the WITHOUT DEFAULTS clause, the current value of the variable linked to the required field is considered as a default value; the runtime system assumes that the field satisfies the required property, even if the variable value is NULL. Note however that in an INPUT ARRAY dialog, the required property applies always to new created rows, even if WITHOUT DEFAULTS is used.
To insist on a non-null entry, use the NOT NULL property instead. The NOT NULL property can be specified in the field definition or in the corresponding column in the database schema file.