As you know, FileMaker can be setup to validate data that is entered into a field. You can setup the validation settings via a number of dialog box controls. When validation fails, you can even give the user a customized warning dialog box.
There is a fairly straight forward and simple way to lock a record so that the information within it CANNOT be edited. This can be done with validation in the key fields you want to protect. Validation will allow information in a record that conforms with the specified validation method. So you can create a field that is used like a light switch. If the switch is on, you are secure and changes cannot be made. If the switch is off, changes can be made.
The first time I used this technique was building a double entry accounting system. In this system, when a record was posted, the accountant did not want the money transaction information to be edited. Posting in an accounting system means that data is locked. Once locked, they are never to be edited. Adjustments have to be handles as their own credit / debit records adjusting the overall values for those accounts.
When a record was posted, information was sent to a FileMaker file called CreditDebit.FP5. If you unlocked a record, those associated records would be deleted and the record was marked as an unposted record.
The technique of field validation as part of a security scheme isn’t used that much anymore. You can do much the same thing by using a privilege set and controlling the edit capabilities via a calculation. However, you might still run across the above technique in some converted database solutions.
© 2007 – Dwayne Wright – dwaynewright.com