You don't have to call makePersistent on an object current managed by a
PersistenceManager. Any updates to fields on this object should cause it to
be marked dirty, and when you close the PersistenceManager, the changes
should be reflected in the datastore.

As an additional note, you might want to look at Java coding conventions:

http://java.sun.com/docs/codeconv/html/CodeConvTOC.doc.html

<http://java.sun.com/docs/codeconv/html/CodeConvTOC.doc.html>The way you've
written your code makes it harder for folks who read Java to try to
understand what you're doing (likely the reason why no one responded
initially).

On Wed, May 26, 2010 at 7:40 AM, fni <[email protected]> wrote:

> I use the following code to update an object from servlet in Google
> App Engine :
>
>    String Time_Stamp="[ 2010-05-26 ]",query="select from
> "+Contact_Info_Entry.class.getName()+" where Contact_Id ==
> '"+Contact_Id+"' order by Contact_Id desc";
>
>    PersistenceManager pm=null;
>    try
>    {
>      pm=PMF.get().getPersistenceManager();
>
>      // note that this returns a list, there could be multiple,
> DataStore does not ensure uniqueness for non-primary key fields
>      List<Contact_Info_Entry>
> results=(List<Contact_Info_Entry>)pm.newQuery(query).execute();
>      Contact_Info_Entry A_Contact_Entry=results.get(0);
>      A_Contact_Entry.Extra_10=Time_Stamp;
>      pm.makePersistent(A_Contact_Entry);
>     }
>    catch (Exception e)
> { Send_Email(Email_From,Email_To,"Check_License_Servlet Error
> [ "+Time_Stamp+" ]",new Text(e.toString()
> +"\n"+Get_Stack_Trace(e)),null); }
>    finally { pm.close(); }
>
> The value "[ 2010-05-26 ]" was in A_Contact_Entry.Extra_10, but it
> seems "pm.makePersistent(A_Contact_Entry);" was not executed.
> The object was not updated and there was no error message, why ? How
> to fix it ?
>
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>


-- 
Ikai Lan
Developer Programs Engineer, Google App Engine
Blog: http://googleappengine.blogspot.com
Twitter: http://twitter.com/app_engine
Reddit: http://www.reddit.com/r/appengine

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