Q174689: HOWTO: Set a Primary Key to Updateable in a View

Article: Q174689
Product(s): Microsoft FoxPro
Version(s): MACINTOSH:3.0b; WINDOWS:2.5,5.0,5.0a,6.0
Operating System(s): 
Keyword(s): kbcode kbDatabase kbHWMAC kbvfp300 kbvfp500 kbvfp600 KbDBFDBC kbMDAC250
Last Modified: 22-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0 
- Microsoft Visual FoxPro for Macintosh, version 3.0b 
- Microsoft Data Access Components version 2.5 
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SUMMARY
=======

By default, when creating a view on a table, any field with a primary key index
is not marked as updateable. This article illustrates how you can mark the
primary key as updateable through the View Designer, and programmatically.

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

View Designer
-------------

To mark the primary key as updateable through the View Designer interface, use
the following steps:

1. Open the view in the View Designer.

2. Click the Update Criteria tab.

3. Click the Update column beside the primary key field.

  NOTE: The Update column has a column header that looks like a pencil. If you
  do not select the Update column and you attempt to INSERT a new record, you
  may receive one of the following errors:

  Connectivity error: [Microsoft][ODBC Visual FoxPro Driver Field
  <fieldname> does not accept null values.

  -or-

  Mandatory not null field - missing or null during insert.

Programmatically
----------------

To mark the primary key as updateable programmatically, use the following steps:

1. Open the Tastrade database in the VFP\Samples\Tastrade\Data folder in Visual
  FoxPro 5.0, or the home(2)+"Tastrade\Data" folder in Visual FoxPro 6.0.

2. Run the following program to create a new SQL view based on the Customer
  table.

        ***********RunFirst.prg***********
        CREATE SQL VIEW MYTEST AS SELECT * FROM CUSTOMER
        DBSETPROP("MYTEST","VIEW","SENDUPDATES",.T.)
        ***********End RunFirst.prg*************

3. Modify the view in the View Designer and note that the primary key is not
  marked for updates.

4. Create a program called MarkPrimary and place the following code in it:

        ************MarkPrimary.prg****************
        PARAMETERS ViewName

        x=ALIAS()
        USE IN 0 &viewname
        PrimKeys = CURSORGETPROP('KeyFieldList',viewname)
        i=1
        remField=PrimKeys
        DO WHILE i <> 0
           nextcomma=AT(remField,",")
           IF nextcomma=0 and len(remfield)=0 THEN
              i=0
              EXIT
           ELSE
              IF nextcomma=0 and LEN(remfield)<>0 then
                 tmpfield=remfield
                 y= DBSETPROP(ViewName + "." + ;
                 tmpField,'Field','UPDATABLE',.T.)
                 i=0
                 EXIT
              ELSE
                 tmpField=SUBSTR(remField,i,NextComma -1)
                 remfield=SUBSTR(remfield,nextcomma + 1)
                 i=nextcomma
                 y= DBSETPROP(ViewName + "." + ;
                 tmpField,'Field','UPDATABLE',.T.)
              ENDIF
           ENDIF
        ENDDO

        SELECT  (viewname)
        USE
        IF NOT EMPTY(x) THEN
           SELECT  (x)
        ENDIF
        **************End MarkPrimary.prg*******************

5. Run the MarkPrimary.prg code by typing the following into the Command
  window:

        DO MARKPRIMARY WITH "MYTEST"

6. Modify the view MyTest in the View Designer and notice that the primary key
  field is now marked for updates.

Additional query words:

======================================================================
Keywords          : kbcode kbDatabase kbHWMAC kbvfp300 kbvfp500 kbvfp600 KbDBFDBC kbMDAC250 
Technology        : kbHWMAC kbOSMAC kbVFPsearch kbAudDeveloper kbMDACSearch kbMDAC250 kbVFP300bMac kbVFP500 kbVFP600 kbVFP500a
Version           : MACINTOSH:3.0b; WINDOWS:2.5,5.0,5.0a,6.0
Issue type        : kbhowto

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