[Qt-interest] Qt5 and SQL

[Jason H]

While I absolutely despise [N]Hiberbate, it sounds like that is what you are 
asking for.

I think a QHibernate could be cool, and we could improve on the hibernate at the 
same time. For instance, I despise Hibernate because it violates DRY principals. 
It requires a XML definition and a code (object) definition, not to mention the 
actual change to the source. If we could use QMetaObject to construct the object 
definition at run- or compile- time, then we'd have a less despicable version. 
(Basically I imagine a file to have a field type preference and lay out the 
relational structure, like the *.hbm.xml files, but we could run it through a 
proxy generator or QMetaObject would create a meta type and register it at run 
time.)

I also think this gets back to the XML DOM stuff, that is we can create a 
relational structure, once we have an instance, we should be able to 
automatically serialize between XML and RDBMS, as well as other structural 
formats like JSON (NoSQL). 




 



----- Original Message ----
From: Linos <info at linos.es>
To: Jason H <scorp1us at yahoo.com>
Cc: Qt-Interest <qt-interest at trolltech.com>
Sent: Wed, May 18, 2011 7:02:11 AM
Subject: Re: Qt5 and SQL

Well i will post any examples but the list could grow really large:

-Better support for Postgresql, any major upgrade break qt applications because 
to detect capabilities of version the driver uses a simple case where unknown 
versions get a broken route where sql models don't works, i sent the patch for 
9.x versions but clearly this should be handled in a better way, and many great 
features like async notifications for update models attached of updated tables 
should be integrated in QT.

-QSqlQueryModel should have the option to work asynchronously, when i have a big 
query it takes many seconds only to finish the exec of the query, only to later 
show the first 15 records in a QTableView.

-in QSqlRelationalModel where a column have a relation set 
model->data(model->index(row, column), Qt::EditRole) should give you the mapped 
id, now you get the same display value that Qt::DisplayRole returns but 
model->SetData works correctly. I have to do get the model and the relation of 
the mapped column and use relModel->match(....) for the display value to get the 
correct row and get the id from this model, if i have two different ids with 
same display value i am out of luck.

-support for custom relations, any times i want to use as display values fields 
in a third table or use something like "name || surname", and any times i have a 
really big table where i only want to let the user select a small subset (where 
filter), use QSqlTableModel like the only way to do the mapping it is not a 
sufficient flexible way to do this.

-a simple way to create forms attached to a simple table would be great too, any 
times i have a really simple database table, but if the table have any foreign 
keys and you want to map to any widgets and such you end with a class that i 
think it is too large for how a such a simple task should be.

-give support for QSqlRelationalDelegate to widgets other than QComboBox, for 
example i have many read only QLineEdit where i want my users see the display 
value.

-give support for QSqlRelationalTableModel and QSqlTableModel to directly set 
any columns as readonly, have to subclass only for this don't seems reasonable 
to me, many times you have column that the users need to see but should not be 
changing.

This is only what i remember just now, i have written any subclasses to do this 
work and much more for me (for example i have a huge QSqlQueryModel subclass 
with write support where i can use joins and such in the query and the model do 
the correct updates or inserts and much more features) but apart from any list 
of features wanted the point it is that QtSql seems to be a bit forgotten by QT 
developers, the support it is not complete (it can clearly improve) but still 
don't get new features from some time ago.

For desktop applications that try to be for companies doing real work with big 
normalized databases the support in Qt should be much better that it is now.

Regards,
Miguel Angel.

El 17/05/11 23:24, Jason H escribió:
> Can you clarify what love you would like QtSQL to get?
> 
> 
> 
> 
> ----- Original Message ----
> From: Linos<info at linos.es>
> To: Qt-Interest<qt-interest at trolltech.com>
> Sent: Sat, May 14, 2011 12:40:43 PM
> Subject: Re: [Qt-interest] Qt5 and XML DOM
> 
> ...
> 
> And from me, QtSql need some love too.
> 
> Regards,
> Miguel Angel.
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