I have a similar problem (I am using SQLite as a on disk local cache for
a list of about 1,000,000 rows and then filtering and sorting that list
as needed) and a slightly different solution, The best way I have come
up with so far is to create a virtual table with a INTEGER PRIMARY KEY
on it - IE

CREATE TEMP TABLE t 
( 
        id INT PRIMARY KEY, 
        v VARCHAR(10) 
);

INSERT INTO t (v) SELECT DISTINCT x FROM foo;

The advantage for me, since each filtered/sorted list has a reasonably
short life time, is that I can then update the underlying table (which
occurs relatively frequently) and then notify myself and update/recreate
my temp tables (you could do this via a trigger) and I also have
guaranteed unblocked reads from my temp table during updates of the
original table allowing me to have near atomic updates of my sub lists
(by creating a new temp table, swaping which one I use and then deleting
the old one).

Not perfect but it seems to work so far..

- James

-----Original Message-----
From: Christian Nassau [mailto:[EMAIL PROTECTED] 
Sent: 13 June 2006 07:41
To: sqlite-users@sqlite.org
Subject: [sqlite] Re: How to realize the ROWID in a view?

I think you could use min(rowids) as your new rowid like this:

sqlite>  create  view v as select x,min(id) as id from foo group by x;
sqlite>  select * from v;
x       id
X       1
Y       2
Z       4

Does this do what you want?


PY wrote:
> Hi All,
>
> I have a problem about the ROWID in a view. I want to simulate a ROWID
in a
> view just like the same purpose in a table.
>
> For Example:
>
> Create Table foo(id INTEGER PRIMARY KEY AUTOINCREMENT, x TEXT);
> insert into foo(x) values('X');
> insert into foo(x) values('Y');
> insert into foo(x) values('X');
> insert into foo(x) values('Z');
>
> Create View v_foo AS
> SELECT distinct(x) FROM foo
> ORDER BY x desc;
>
>
> SELECT * from foo;
>
> id          x
> ----------  ----------
> 1           X
> 2           Y
> 3           X
> 4           Z
>
>
> My expect result of "select * from v_foo;" is
>
> id          x
> ----------  ----------
> 1           Z
> 2           Y
> 3           X
>
>
>
> Would you please help to tell me how to finish that?
> Thanks for your grest help.
>
>
>
>
> Thanks,
> VK
>

Reply via email to