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From exxos <hat...@gmail.com>
Subject Re: Why the connection is given two times in case of UPDATE?
Date Mon, 16 Aug 2010 06:59:23 GMT
Hi Rainer,

Thank you for your reply.

Could you please just give a short example on how to perform an UPDATE with
a DBCommand?

Regards,
exxos.


On Sun, Aug 15, 2010 at 11:04 PM, Rainer Döbele <doebele@esteam.de> wrote:

>  Hi exxos,
>
>
>
> In your update example the call to rec.read() will read the record from the
> database by executing a corresponding SELECT statement.
>
> The UPDATE then only updates the changed fields.
>
>
>
> It is part of our design, that we don’t store connections since they are an
> external resource that might be shared between threads or requests and hence
> a connection must be supplied every time a database action is performed. But
> you may add your own layer (e.g. by deriving a class from DBRecord) to
> implement a connection handling that suits your purpose.
>
>
>
> If you don’t want to read before an update – e.g. if you know that the
> value will change and don’t need the extra logic – then you should use a
> DBCommand to update a record.
>
>
>
> Regards,
>
> Rainer
>
>
>
>
>
> *from:* exxos [mailto:hatufr@gmail.com]
> *to:* empire-db-user@incubator.apache.org
> *re:* Why the connection is given two times in case of UPDATE?
>
>
>
> Hello,
>
>
>
> Sorry to spam the august's mailling list. ^__^
>
>
>
> But, I need a clarification on the implementation for the INSERT and the
> UPDATE methods.
>
>
>
> Accroding you tutorial, the following steps are needed:
>
>
>
> // INSERT
> DBRecord rec = new DBRecord();
> rec.create(DBRowSet table);
> rec.setValue(...)
> rec.update(java.sql.Connection conn);
>
>
>
> // UPDATE
> DBRecord rec = new DBRecord();
> rec.read(..., java.sql.Connection conn);
> rec.setValue(...)
> rec.update(java.sql.Connection conn);
>
>
> Why in case of the UPDATE we have to give the Connection by two times?
>
>
>
> Thank to advise,
>
> Regards.
>
>
>
>
>

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