Hey,
2014-03-17 12:14 GMT+01:00 Tor Arne Fallingen <fallin...@gmail.com>:
> Hey,
>
> Ive come to the point where I need to make a db handler class for our
> project. I have a few things I need to be able to do, and that is either
> creating a new job (which is only a new id number for a job, the table
> could be the same, or a new table could be made), then I wish to be able to
> modify my db data. What I was looking for was some way of initiating a
> database connection in one method, and then I want to be able to send that
> connection/session to my methods. Is this possible, or would I have to
> initiate a connection for each task I want to do, and then close it again
> after committing my data? I will log gps data, so Id like to make a
> connection, then repeat my «submit gps data» every time I get a new valid
> string.
>
> The way I see it in the tutorial, I see only a connection being set up
> within the method before doing all tasks the example calls for. Im not sure
> if this makes sense, and I would go at it trying different angles a whole
> lot longer, but we are running out of time here, so Im hoping to be able to
> get some help here. Basically this is how Id wish to be able to do it:
>
> Session dbSession(){
> Wt::Dbo::backend::MySQL mysql("db", "root", «pass", "127.0.0.1", 3306);
>
> mysql.setProperty("show-queries", "true");
>
> Wt::Dbo::Session session;
>
> session.setConnection(mysql);
>
>
> return session;
>
>
> }
>
>
The first problem with this is that the 'mysql' object is a local object
that is deleted after returning from this method. It needs to survive the
session lifetime. So if you change it to a heap-allocated object then this
will work. The second problem is the fact that you are returning the
session by value, which you cannot do. So this should probably also be a
heap-allocated object.
There certainly is no problem with reorganizing the code to have the
session setup separately from the actual usage; this is done in the blog
example as well.
Regards,
koen
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