HOWTO: Setting a Primary Key to Updateable in a View

• Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a
• Microsoft Visual FoxPro for Macintosh, version 3.0b

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.

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.

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.

Keywords          : FxprgTable VFoxMac vfoxwin kbcode
Version           : MACINTOSH:3.0b; WINDOWS:5.0,5.0a
Platform          : MACINTOSH WINDOWS
Issue type        : kbhowto