I have a R/O cursor that is an extract from a table. I need it
to be R/W so I can run some a what-if scenario on it. I would rather
not create a table since I do not want to keep the data. How can I
create a R/W version of the cursor that I have?

Failing that, how can I create a R/W extract from a table? (The
original table must not be modified by the subsequent writes.)

Sincerely,

Gene Wirchenko

You can use this against a SQL SELECT R/O cursor :

*
* From BostonComputerNewsNetwork @NJ Fox-user 6-22-94
*+
*PURPOSE:
* To Make SQL read-only cursor into R/W cursor
* Must be real file not filtered view
*
*SYNTAX:
* m.retstat = mkcursrw(m.cn)
*PARAMETERS:
* m.cn -(C) Cursor alias name to be made read/writable.
*
*RETURNS:
* m.retstat -(L) .t. made the read-only cursor to R/W cursor.
* .f. the cursor alias name does not correspend
* to a cursor.
*REMARKS:
*SEE ALSO:
*-
*
FUNCTION mkcursrw
PARAMETER m.cn
PRIVATE m.cf, m.retstat
m.cf = DBF(m.cn)
IF ".TMP"=RIGHT(m.cf,4)
USE (m.cf) AGAIN IN 0 ALIAS dummycname
USE IN (m.cn)
USE (m.cf) AGAIN IN 0 ALIAS (m.cn)
USE IN dummycname
SELECT (m.cn)
m.retstat = .t.
ELSE
m.retstat = .f.
ENDIF
RETURN m.retstat


--
Fred
Microsoft Visual FoxPro MVP


"Gene Wirchenko" <genew (AT) ucantrade (DOT) com.NOTHERE> wrote

Hi Gene,

If you add a dummy field to the field list, then Foxpro mostly builds a separate
cursor which is writable.
Something like
SELECT *, "" as dummy FROM ... INTO CURSOR ...
should do the trick.
Another way:
CREATE a new cursor from the structure of your R/O cursor and append the rows
from R/O cursor.

Regards
Bernhard Sander

[readded comp.databases.xbase.fox]
[reordered to chronological]

On Wed, 28 Jun 2006 09:29:54 -0400, "Dan" <delliott (AT) midwestecoat (DOT) com>
wrote:

This worked nicely. Thank you.

Sincerely,

Gene Wirchenko

[corrected deleted attribution]

On Wed, 28 Jun 2006 10:12:03 +0200, Bernhard Sander
<fuchs (AT) individsoft (DOT) de> wrote:

No. I created the cursor with nofilter. This from the VFP 6
On-line Docs:

CURSOR CursorName [NOFILTER], which stores query results in a cursor.
If you specify the name of an open table, Visual FoxPro generates an
error message. After SELECT is executed, the temporary cursor remains
open and is active but is read-only. Once you close this temporary
cursor, it is deleted. Cursors may exist as a temporary file on the
drive or volume specified by SORTWORK.

Why the cursor ends up R/O makes no sense to me, but that is how
it is documented and how VFP 6 behaves.

It did not work for me. VFP said that the cursor was R/O. This
is an old trick to avoid a filter.

That did work. Someone posted code for this.

Sincerely,

Gene Wirchenko

You can also get a read-write cursor from a read-only cursor like this:

Use DBF("read-only-alias") Again Alias RWCursor

It's completely undocumented, but it still works in VFP9 (where it's also
unnecessary <g>).

Dan

Gene Wirchenko wrote: