Q141441: How to Create Validation Rules on Views

Article: Q141441
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,3.0b
Operating System(s): 
Keyword(s): kbcode
Last Modified: 04-AUG-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b 
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SUMMARY
=======

You can easily create field and row level validation rules for Visual FoxPro
Tables by using the Table Designer. For local and remote views, however, the
View Designers do not give you a way to visually create validation rules. For
views, validation rules must be created programmatically by using dbsetprop().

MORE INFORMATION
================

Step-by-Step Example
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1. Create an Updatable Local View:

  a. Open the TestData database in Samples\Data under the main Visual FoxPro
     directory.

  b. On the File menu, click New. Select View as the file type, and then click
     New File.

  c. Select EMPLOYEE from the Add Table or View list.

  d. In the Fields tab of the View Designer, click Add All to move all fields
     to selected output.

  e. In the Update Criteria tab, ensure that EMP_ID is marked as the key field
     and all other fields are marked as Updatable (they should have a check
     mark in the pencil column). click the Send SQL Updates button.

  f. Under the SQL WHERE clause options, select Key Fields only, and then save
     the view as EMP_VIEW.

2. Create a row-level Validation Rule to ensure that the Hire_date is later than
  the Birth_date:

  a. Type the following in the Command window:

        =dbSetProp("Emp_view","View","RuleExpression",;
            "Hire_date >Birth_date")
        =dbSetProp("Emp_view","View","RuleText",";
            'Hire date must be after birth date' ")
        USE Emp_view
        BROWSE

  b. Change the value of hire_date to be earlier than birth_date, and then move
     off the record. The validation rule fires and the error message is
     displayed.

3. Create a field level Validation Rule to ensure that the Last_name is not
  empty by typing the following in the Command window:

     =dbSetProp("emp_view.last_name","field","RuleExpression",;
        "not empty(last_name)")
     =dbSetProp("emp_view.last_name","field","RuleText",;
         " 'Last name cannot be blank' ")
     USE Emp_view
     BROWSE

Deleting the contents of the last name field and moving to the next field causes
the validation rule to fire.

(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by Kevin
Zollman, Microsoft Corporation.


Additional query words: VFoxWin akz

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Keywords          : kbcode 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b
Version           : WINDOWS:3.0,3.0b

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