Siebel Developer's Reference > Operators, Expressions, and Conditions >
Calculated Field Rules
Calculated fields have the following rules and restrictions:
- Calculated fields do not support updates (even simple expressions like [Field]), unless specialized business components override SqlSetFieldValue.
- For a calculated field whose calculated value is not of type DTYPE_TEXT, the field type must be specified explicitly.
- Calculated fields cannot be stored in columns.
- Validation criteria on calculated fields are ignored.
- Queries on calculated fields are always supported.
When a query is performed on a calculated field, the action taken by your Siebel application (and thus the resulting performance) depends on which functions are used within the calculation. Functions that can be incorporated directly into the WHERE clause in the SQL statement are incorporated. Functions that cannot be directly incorporated, such as IIf() and Lookup(), result in testing each record in the business component to determine which records to display to the user, at a considerable performance cost.
- Sorting on calculated fields is never supported.
- A calculated field may be based on the results of another calculated field in the same business component. There is no limitation on the number of levels of calculated fields based on other calculated fields.
- You can put hyperlinks in calculated fields by using the <a href= ...></a> HTML tag.