Record-Level Rule Checking

Record-level rules, like field-level rules, activate when the record value changes. No matter how you work with data, whether in a Browse window, form, or other user interface window, or through commands that alter data, Visual FoxPro checks record-level rules as you move the record pointer off the record. If no values within the record have changed, the record-level rule is not checked when you move the record pointer. You are free to move through records without the system validating any of the data.

If you modify a record, but don't move the record pointer, and then close the Browse window, the rule is still checked. You're warned of any errors that occur, and the Browse window is closed.

Caution   Do not include any commands or functions in your validation rules that attempt to move the record pointer in the current work area (that is, in the work area whose rules are being checked). Including commands or functions such as SEEK, LOCATE, SKIP, APPEND, APPEND BLANK, INSERT, or AVERAGE, COUNT, BROWSE, and REPLACE FOR in validation rules may cause them to trigger recursively, creating an error condition.

Unlike triggers, record-level rules fire even if data is buffered. When a record-level rule fires during a running application, you need to include error-handling code. Typically, this will mean not allowing the application to leave the form (or change the active environment, to be more generic) until the user either corrects the reported error or cancels the update.

Removing a Table with Associated Rules from a Database

If you remove or delete a table from a database, all field-level and record-level rules bound to that table are deleted from the database. This is because the rules are stored in the .dbc file, and removing a table from the database breaks the link between the .dbf file and its .dbc file. However, stored procedures referenced by the removed or deleted rule are not deleted. They are not automatically removed, because they may be used by rules in other tables that remain in the database.

See Also

Knowing When Field-Level Rules Are Checked | Trigger Usage | Working with Tables | Enforcing Business Rules | Creating Triggers | Controlling Display of a Field