When a user finishes entering segment values in a flexfield pop-up window, the flexfield checks whether the values make up a valid combination before updating the database. If the user entered an invalid combination, a diagnostic error message appears, and the cursor returns to the first segment assumed to contain an invalid value.
Cross-validation rules control combinations of values within a particular key flexfield structure. Cross-validation applies to combinations users attempt to create using either the combinations form or foreign key forms (using dynamic inserts).
Cross-Validation Rules and Existing Combinations
Cross-validation rules have no effect on combinations that already exist when you define your cross-validation rules.
Suppose you define a new cross-validation rule, but have existing entries in your combinations table that violate the rule. Since the existing combinations pre-date the rule, your flexfield continues to treat them as valid. However, if your end user tries to create a new combination that violates your new rule, your flexfield returns an error message and rejects the combination.
If you want to prevent users from using previously-existing combinations that are no longer valid according to your cross-validation rules, you can always manually disable those combinations using the combinations form.
Dynamic Insertion and Cross-Validation
Your use of cross-validation is separate from (and in addition to) your use of dynamic inserts.
By allowing dynamic inserts, you can let users create new combinations automatically upon entering the combination in a foreign key form (any form other than the combinations form) and in the combinations form itself.
If you want greater control, you can disallow dynamic inserts. You can thus restrict the creation of new combinations to certain authorized people who have access to the combinations form on their menu. You simply turn dynamic insertion off using the Define Key Flexfield Segments form. Depending on the key flexfield you use, you can still create new combinations using one of your product setup forms (the combinations form). For example, if you use the Accounting Flexfield, you can enter new combinations using the Define Accounting Flexfield Combination form.
In either case, however, there is no inherent protection against a user creating an invalid new combination. Cross-validation rules ensure that nobody can create invalid new combinations from either foreign key forms or the combinations form, regardless of whether you allow dynamic inserts.
As you consider the controls you want over your key flexfield combinations, determine whether you need cross-validation rules at all. To provide an extra level of security, use cross-validation rules even if you turn dynamic insertion off. This allows you to double-check new combinations that even your authorized personnel enter using the combinations form.
Changing your key flexfield structure after defining rules
Changing an existing key flexfield structure may adversely affect the behavior of any cross-validation rules you have for that structure, so you should be sure to manually disable or redefine any cross-validation rules to reflect your changed structure. Flexfield structure changes that make your existing rules invalid include:
          o changing the order of segments
          o adding a new segment
          o disabling a segment
          o changing segment lengths
For example, if you change a six-segment structure to contain only five segments, you would not be able to use any new five-segment code combinations since any rules existing for the old six-segment structure would be violated.
Cross-Validation Rules Window
Your flexfield checks cross-validation rules while attempting to create a new combination of flexfield values (for example, a new Accounting Flexfield combination). Your cross-validation rules have no effect on flexfield combinations that already exist. If you want to disable an existing combination, you must disable that combination specifically using the appropriate window. For example, you can disable an existing Accounting Flexfield combination using the Define Accounting Flexfield Combinations window.
    Suggestion: We recommend that you define many rules that each have few rule elements rather than a few rules that each have many rule elements. The more rules you provide, the more specific you can make your error message text.
Your flexfield checks cross-validation rules only if you set Cross-Validate Multiple Segments to Yes using the Define Key Flexfield Segments window.
If you make changes to your cross-validation rules, you need to either change responsibilities or exit from your application and sign on again in order for the changes to take effect.
Oracle Applications provides many key flexfields, such as the Accounting Flexfield, Location Flexfield and System Items Flexfield. In this essay, we use the Accounting Flexfield to present suggestions for designing your cross-validation rules, but you can use cross-validation rules for any key flexfield structure that has cross-validation enabled.
Use the Key Flexfield Segments window to define your flexfield structure and segments and specify Yes in the Cross-Validate Multiple Segments field for your flexfield structure.
To define cross-validation rules:

  1. Select the name and structure of your key flexfield for which you wish to define cross-validation rules. Your list only contains structures with the field Cross-Validate Multiple Segments set to Yes on the Key Flexfield Segments window.
  2. Enter a unique name and a description for your cross-validation rule.
  3. Enter your error message text for this cross-validation rule.                                                                                  Your flexfield automatically displays this error message on the message line whenever a new combination of segment values violates your cross-validation rule. You should make your error messages as specific as possible so that your users can correct any errors easily.
  4. Enter the name of the segment most likely to have caused this cross-validation rule to fail. Your flexfield leaves the cursor in this segment whenever a new segment combination violates this cross-validation rule to indicate where your user can probably correct the error. If you do not specify an error segment name, your flexfield leaves the cursor in the first segment of the flexfield window following a violation of this rule.
  5. If you want to have the rule effective for a limited time, you can enter a start date and/or an end date for the rule. The rule is valid for the time including the From and To dates.
  6. Define the cross-validation rule elements that make up your rule. See: Defining Cross-validation Rule Elements.
  7. Save your changes.

Defining Cross-validation Rule Elements

Use this block to define the cross-validation rule elements that make up your cross-validation rule. You define a cross-validation rule element by specifying a value range that includes both a low and high value for each key segment. A cross-validation rule element applies to all segment values included in the value ranges you specify. You identify each cross-validation rule element as either Include or Exclude, where Include includes all values in the specified ranges, and Exclude excludes all values in the specified ranges. Every rule must have at least one Include rule element, since a rule automatically excludes all values unless you specifically include them. Exclude rule elements override Include rule elements.
 Suggestion: We recommend that you define one all-encompassing Include rule element and several restricting Exclude rule elements.
Select the type of cross-validation rule element. Valid types are:
Include     Your user can enter any segment value combinations that fall in the following range.
Exclude     Your user cannot enter any segment value combinations that fall in the following range.
When you enter the From (low) field, this window automatically displays a window that contains a prompt for each segment in your flexfield structure. You enter both the low and high ends of your value range in this window. After you finish entering your ranges, this zone displays your low segment values in concatenated window in the Low field and displays your high segment values similarly in the High field.
Enter the low end and the high end of your segment combination range. Neither the low nor the high combination has to be a valid key flexfield combination, nor do they need to be made up of valid segment values.
Note that a blank segment value (null value) is considered to fall within a range that has one or both ends specified as a blank. However, if all of your segments require a value, you would not be able to create a combination with a blank segment anyhow.
You may use blank minimum or maximum segment values to create cross-validation rules that can test for blank segments (that are not already required to have a value). For example, if you allow a null value for your last optional segment but not the second-to-last optional segment, you would use a blank minimum or maximum value for the last segment but fill in a value (such as 000 or 999) for both the minimum and maximums for the second-to-last optional segment.
If you want to specify a single combination to include or exclude, enter the same combination in both the Low and High fields.
Disabled rules are ignored when your key flexfield validates a combination of segment values. Deleting the rule has the same effect, but you can re-enable a disabled rule.

A key flexfield can perform automatic cross-validation of segment values according to rules your organization defines when you customize the key flexfield. You can use cross-validation to closely control the creation of new key flexfield combinations, and you can maintain a consistent and logical set of key flexfield combinations that you need to run your organization.
What is Cross-Validation?
Cross-validation (also known as cross-segment validation) controls the combinations of values you can create when you enter values for key flexfields. A cross-validation rule defines whether a value of a particular segment can be combined with specific values of other segments. Cross-validation is different from segment validation, which controls the values you can enter for a particular segment.
You use cross-validation rules to prevent the creation of combinations that should never exist (combinations with values that should not coexist in the same combination). For example, if your organization manufactures both computer equipment and vehicles such as trucks, you might want to prevent the creation of “hybrid” part numbers for objects such as “truck keyboards” or “CPU headlights”.

As another example, if you use the Accounting Flexfield, you may decide that all revenue accounts must have a department. Therefore, all your “revenue” account values (such as all values between 4000 and 5999) must have a corresponding department value other than 000 (which means “non-specific”).

For example, suppose you have an Accounting Flexfield where you have a Company or Organization segment with two possible values, 01 and 02. You also have a Natural Account segment, with many possible values, but your company policy requires that Company or Organization 01 uses the natural account values 001 to 499 and Company or Organization 02 uses the natural account values 500 to 999. You can create cross-validation rules to ensure that users cannot create a GL account with combinations of values such as 02-342 or 01-750, for example.