Yes, that's what I meant.
Always call getWritableDatabase, and don't call
SQLiteDatabase.openDatabase - are you, perhaps, somewhere in your code?
In the link you posted, table upgrades are done by renaming the old
table and creating a new table from scratch, then copying the data. So
there is the time period when the table doesn't exist. Most likely, this
is the reason why you're seeing your error.
Since you've said that your code is multithreaded, I think what happens
is, one thread starts upgrading the database, while another thread
starts to make queires, or perhaps tries to perform an upgrade as well.
To fix this issue, you need to add thread synchronization around opening
the database, to avoid concurrent access until the database has been
fully upgraded.
-- Kostya
22.10.2010 17:03, Alok Kulkarni пишет:
I am following this
http://efreedom.com/Question/1-3505900/SQLiteOpenHelper-OnUpgrade-Confusion-Android
What do u mean by saying "SQL open helper for all code paths"
I am using the standard code for
public void open() throws SQLException {
db = DBHelper.getWritableDatabase();
}
The open method is called for each database seperately.
On Fri, Oct 22, 2010 at 6:26 PM, Alok Kulkarni<kulsu...@gmail.com> wrote:
Yeah ill do my best.. My code is too complicated right now... :P
One more thing i need to confirm.. After upgrade , all the old
databases are deleted right.. So i need to backup all the tables in
the onUpgrade and recreate new ones .. Right ?
On Fri, Oct 22, 2010 at 6:20 PM, Kostya Vasilyev<kmans...@gmail.com> wrote:
Sounds like this could be it.
Can't you just go through SQL open helper for all code paths?
-- Kostya
22.10.2010 16:37, Alok Kulkarni пишет:
No. Actually i am accessing another table from my databases at the
same time from another thread while onUpgrade is being called.So i
think thats where the problem lies.But i need to figure out a way so
that i access the SQL tables after the on Upgrade function completes.
On Fri, Oct 22, 2010 at 5:58 PM, Kostya Vasilyev<kmans...@gmail.com>
wrote:
AFAIK, there is nothing special, except:
- onUpgrade may take some time to run
- the tables are not updated until after onUpgrade is done
Are you accessing the database in any way bypassing your SQL open helper?
Is this what you mean by "
At the start of the application ,
i initialize all the databases and access columns from the required
tables
"
?
If you're relying on SQL open helper and its onUpgrade, then that should
be
the only way you're accessing the database.
-- Kostya
22.10.2010 15:14, Alok Kulkarni пишет:
Hi,
I have multiple databases in my app.At the start of the application ,
i initialize all the databases and access columns from the required
tables.What i did is , for one of the databases i incremented the
version of the DB. So now i have started getting error of " No Such
table say ABCD while compiling " query.This table is in another DB
than the updated DB. I dont have any code in the onUpgrade right now..
Is there any thing thats striking anyone why this behavior is
happening? Is there anything that happens in the onUpgrade method that
causes all the DBs to be inaccessable temporarily. I am saying this
because if i place a breakpoint in onUpgrade and debug , then i wait
for a few seconds on the 1st stmt in onUpgrade and then everything
works fine...
--
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http://kmansoft.wordpress.com
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