I got this off the UT. Enjoy.
>Can anyone give me the skinny on how this works? (Behind-the-scenes stuff.)
>
>Thanks in Advance.
There is a tiny mouse cage. In the cage is a spinning wheel. There is also a
lepracan. When you add a record the lepracan temps the mouse with a piece of
magic cheese. This causes the mouse to run in the wheel, and VFP counts the
wheel rotations. The lepracaun just knows by magic when to give the mouse
the cheese... so, you get the next id.
Actually, I believe a few bytes unused in the .dbf header was stolen to
store the next id value. If you already have values, when you change the
type to auto-increment you can specify the 'next id' so it wont conflict
with your existing numbers.
Bob Archer
Stephen Russell
President
S.R. & Associates
Memphis TN
901.246-0159
You can also reset it to 0 if you've ZAPped the table.
Here's how GenDBC does it:
CREATE TABLE 'TEST1.DBF' NAME 'TEST1' (FIELD1 C(10) NOT NULL, ;
FIELD2 I NOT NULL, ;
FIELD3 M NOT NULL, ;
FIELD4 I NOT NULL AUTOINC NEXTVALUE 5 STEP 3)
Cindy Winegarden MCSD, Microsoft Visual FoxPro MVP
cindy.winegarden@mvps.org=20
-----Original Message-----
From: profox-admin@leafe.com [mailto:profox-admin@leafe.com] On Behalf =
Of
Stephen Russell
Sent: Friday, February 07, 2003 9:46 AM
To: profox@leafe.com
Subject: Secret to Auto Increment ID in VFP8
I got this off the UT. Enjoy.
>Can anyone give me the skinny on how this works? (Behind-the-scenes =
stuff.)
>
>Thanks in Advance.
There is a tiny mouse cage. In the cage is a spinning wheel. There is =
also a
lepracan. When you add a record the lepracan temps the mouse with a =
piece of
magic cheese. This causes the mouse to run in the wheel, and VFP counts =
the
wheel rotations. The lepracaun just knows by magic when to give the =
mouse
the cheese... so, you get the next id.
Actually, I believe a few bytes unused in the .dbf header was stolen to
store the next id value. If you already have values, when you change the
type to auto-increment you can specify the 'next id' so it wont conflict
with your existing numbers.
Bob Archer
Stephen Russell
President
S.R. & Associates
Memphis TN
901.246-0159
[excessive quoting removed by server]