Hi Satish,

This question has come up before in various guises. The answer is
basically:

1) GWT is a client side AJAX toolkit - it is back end agnostic and you
do not access e.g. databases directly from GWT client code
2) Instead you use asynchronous calls to your server (using e.g. GWT
RPC) that return Data Transfer Objects representing views of your
database schema.
3) If you use GWT RPC, then you can manage your DB transactions from
your remote RPC servlets server side using e.g. JDBC.

There so many different use case situations that it is unrealistic to
standardize examples of this, but there are plenty of tutorial
resources available on how to use JDBC around.

However in a simple case you might think of it like this:

a) you have a set of database tables representing your domain
entities.
b) you write a DTO class for each of these tables representing one row
of the table (i.e. you basically have a field for each column)
c) you use JDBC to execute SQL query statements in your RemoteServlets
(use PreparedStatement) to instantiate DTO's which you then return to
your GWT client over RPC and you populate your widgets with the values
of these DTO's.
d) on the client side when you need to create/update and save a new/
changed entity instance, you strip vlaues from your UI widgets to
create a new DTO instance for the entity and dispatch this DTO to the
server over RPC for storage
e) you use then JDBC to execute SQL update statements in a remote
servlet using the values from this DTO.

This is of course likely to be an over-simplification, but it is the
basis of a typical approach for connecting a GWT client to a back end
database resource.

regards
gregor



On Sep 18, 10:15 am, satish <[EMAIL PROTECTED]> wrote:
> hi
> am new to this GWT
> is there any ready to  run examples on CRUD in this gwt using derby as
> backend
> if yes please provide me
> any suggestions would be helpful for me
>
> thankhs
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"Google Web Toolkit" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at 
http://groups.google.com/group/Google-Web-Toolkit?hl=en
-~----------~----~----~----~------~----~------~--~---

  • CRUD satish
    • Re: CRUD gregor

Reply via email to