DOCUMENT:Q141441  04-AUG-2000  [foxpro]
TITLE   :How to Create Validation Rules on Views
PRODUCT :Microsoft FoxPro
PROD/VER:WINDOWS:3.0,3.0b
OPER/SYS:
KEYWORDS:kbcode

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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
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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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