Qt-interest Archive, May 2007
Knowing if sqlite database exists
Pages: Prev | 1 | 2 | Next
Message 1 in thread
Hello all,
I have an application using sqlite, however, in the first run I need
to create the database tables and initialize some other stuff. How can
I check if it is the first run or not, i.e. if I need to call the
function for table creation?
Cheers,
--
[ signature omitted ]
Message 2 in thread
Hello, Paulo J. Matos
12.05.2007 19:06 you wrote:
> Hello all,
>
> I have an application using sqlite, however, in the first run I need
> to create the database tables and initialize some other stuff. How can
> I check if it is the first run or not, i.e. if I need to call the
> function for table creation?
>
> Cheers,
>
Check if tables already exists with QSqlDatabase::tables, or tables
structure with QSqlDatabase::record ?
--
[ signature omitted ]
Message 3 in thread
On 5/14/07, Nikolay Moskvichev <nikolay.moskvichev@xxxxxxxxx> wrote:
> Hello, Paulo J. Matos
> 12.05.2007 19:06 you wrote:
> > Hello all,
> >
> > I have an application using sqlite, however, in the first run I need
> > to create the database tables and initialize some other stuff. How can
> > I check if it is the first run or not, i.e. if I need to call the
> > function for table creation?
> >
> > Cheers,
> >
>
> Check if tables already exists with QSqlDatabase::tables, or tables
> structure with QSqlDatabase::record ?
>
Ah, that's the cool solution, I think.
Thank you very much! :D
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
>
>
>
>
--
[ signature omitted ]
Message 4 in thread
Hello,
I am using Qt4 and would like to load files that are dropped anywhere
within the main window of my application. I do this by installing an
event filter but I am stuck at the point where I need to extract the
path and name of the file that was dropped. The format of the MIME data
of the drop event is:
application/x-qt-windows-mime;value="Shell IDList Array"
This is a Windows format with an array of PIDLs which is not exactly
what I would like to deal with. Is there any way to obtain the path and
name of the file in a non-platform-specific way? It feels like I am
making an easy thing into something complicated here.
Best Regards,
Daniel Hedberg
--
[ signature omitted ]
Message 5 in thread
drag&drop data typically comes in multiple flavors.
you probably want to pick some other mime type...
if (event->mimeData()->hasFormat("text/plain"))
...
Cheers,
Peter
> -----Ursprüngliche Nachricht-----
> Von: Daniel Hedberg [mailto:daniel.hedberg@xxxxxxxxxxxx]
> Gesendet: Montag, 14. Mai 2007 14:10
> An: qt-interest@xxxxxxxxxxxxx
> Betreff: Drag & Drop of files.
>
> Hello,
>
> I am using Qt4 and would like to load files that are dropped anywhere
> within the main window of my application. I do this by installing an
> event filter but I am stuck at the point where I need to extract the
> path and name of the file that was dropped. The format of the MIME data
> of the drop event is:
>
> application/x-qt-windows-mime;value="Shell IDList Array"
>
> This is a Windows format with an array of PIDLs which is not exactly
> what I would like to deal with. Is there any way to obtain the path and
> name of the file in a non-platform-specific way? It feels like I am
> making an easy thing into something complicated here.
>
> Best Regards,
> Daniel Hedberg
>
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
> "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
--
[ signature omitted ]
Message 6 in thread
Problem is that the data is generated by MS Windows as I am dragging a file from the MS Windows file explorer and dropping it on my window.
Therefore, event->mimeData()->hasFormat("text/plain") returns false.
I thought maybe Qt had some mechanism for handling this in a platform independent way. This was possible in Qt3 as the MIME data actually was plain text, but in Qt4 it is not.
Best Regards,
Daniel Hedberg
-----Original Message-----
From: Peter Prade [mailto:prade@xxxxxxxxxxx]
Sent: den 14 maj 2007 17:17
To: qt-interest@xxxxxxxxxxxxx
Subject: AW: Drag & Drop of files.
drag&drop data typically comes in multiple flavors.
you probably want to pick some other mime type...
if (event->mimeData()->hasFormat("text/plain"))
...
Cheers,
Peter
> -----Ursprüngliche Nachricht-----
> Von: Daniel Hedberg [mailto:daniel.hedberg@xxxxxxxxxxxx]
> Gesendet: Montag, 14. Mai 2007 14:10
> An: qt-interest@xxxxxxxxxxxxx
> Betreff: Drag & Drop of files.
>
> Hello,
>
> I am using Qt4 and would like to load files that are dropped anywhere
> within the main window of my application. I do this by installing an
> event filter but I am stuck at the point where I need to extract the
> path and name of the file that was dropped. The format of the MIME data
> of the drop event is:
>
> application/x-qt-windows-mime;value="Shell IDList Array"
>
> This is a Windows format with an array of PIDLs which is not exactly
> what I would like to deal with. Is there any way to obtain the path and
> name of the file in a non-platform-specific way? It feels like I am
> making an easy thing into something complicated here.
>
> Best Regards,
> Daniel Hedberg
>
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
> "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
--
[ signature omitted ]
Message 7 in thread
Maybe you could parse the returned value of QMimeData::formats() to see
if you can work with one of formats (if any other format that window is
returned of course!)
Daniel Hedberg a écrit :
>Problem is that the data is generated by MS Windows as I am dragging a file from the MS Windows file explorer and dropping it on my window.
>
>Therefore, event->mimeData()->hasFormat("text/plain") returns false.
>
>I thought maybe Qt had some mechanism for handling this in a platform independent way. This was possible in Qt3 as the MIME data actually was plain text, but in Qt4 it is not.
>
>Best Regards,
>Daniel Hedberg
>
>-----Original Message-----
>From: Peter Prade [mailto:prade@xxxxxxxxxxx]
>Sent: den 14 maj 2007 17:17
>To: qt-interest@xxxxxxxxxxxxx
>Subject: AW: Drag & Drop of files.
>
>drag&drop data typically comes in multiple flavors.
>you probably want to pick some other mime type...
>
>if (event->mimeData()->hasFormat("text/plain"))
> ...
>
>Cheers,
>Peter
>
>
>
>>-----Ursprüngliche Nachricht-----
>>Von: Daniel Hedberg [mailto:daniel.hedberg@xxxxxxxxxxxx]
>>Gesendet: Montag, 14. Mai 2007 14:10
>>An: qt-interest@xxxxxxxxxxxxx
>>Betreff: Drag & Drop of files.
>>
>>Hello,
>>
>>I am using Qt4 and would like to load files that are dropped anywhere
>>within the main window of my application. I do this by installing an
>>event filter but I am stuck at the point where I need to extract the
>>path and name of the file that was dropped. The format of the MIME data
>>of the drop event is:
>>
>>application/x-qt-windows-mime;value="Shell IDList Array"
>>
>>This is a Windows format with an array of PIDLs which is not exactly
>>what I would like to deal with. Is there any way to obtain the path and
>>name of the file in a non-platform-specific way? It feels like I am
>>making an easy thing into something complicated here.
>>
>>Best Regards,
>>Daniel Hedberg
>>
>>--
>>To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
>>"unsubscribe" in the subject or the body.
>>List archive and information: http://lists.trolltech.com/qt-interest/
>>
>>
>
>--
>To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with "unsubscribe" in the subject or the body.
>List archive and information: http://lists.trolltech.com/qt-interest/
>
>--
>To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with "unsubscribe" in the subject or the body.
>List archive and information: http://lists.trolltech.com/qt-interest/
>
>
>
>
Message 8 in thread
Ah, yes... that works! I was so focused on the text/plain" format that I missed the "text/uri-list" format which works perfectly well! Thank you Veronique (and Peter) for pointing me in the right direction!
Best Regards,
Daniel Hedberg
________________________________
From: veronique.lefrere@xxxxxx [mailto:veronique.lefrere@xxxxxx]
Sent: den 14 maj 2007 18:29
To: qt-interest@xxxxxxxxxxxxx
Subject: Re: Drag & Drop of files.
Maybe you could parse the returned value of QMimeData::formats() to see
if you can work with one of formats (if any other format that window is returned of course!)
Daniel Hedberg a écrit :
Problem is that the data is generated by MS Windows as I am dragging a file from the MS Windows file explorer and dropping it on my window.
Therefore, event->mimeData()->hasFormat("text/plain") returns false.
I thought maybe Qt had some mechanism for handling this in a platform independent way. This was possible in Qt3 as the MIME data actually was plain text, but in Qt4 it is not.
Best Regards,
Daniel Hedberg
-----Original Message-----
From: Peter Prade [mailto:prade@xxxxxxxxxxx]
Sent: den 14 maj 2007 17:17
To: qt-interest@xxxxxxxxxxxxx
Subject: AW: Drag & Drop of files.
drag&drop data typically comes in multiple flavors.
you probably want to pick some other mime type...
if (event->mimeData()->hasFormat("text/plain"))
...
Cheers,
Peter
-----Ursprüngliche Nachricht-----
Von: Daniel Hedberg [mailto:daniel.hedberg@xxxxxxxxxxxx]
Gesendet: Montag, 14. Mai 2007 14:10
An: qt-interest@xxxxxxxxxxxxx
Betreff: Drag & Drop of files.
Hello,
I am using Qt4 and would like to load files that are dropped anywhere
within the main window of my application. I do this by installing an
event filter but I am stuck at the point where I need to extract the
path and name of the file that was dropped. The format of the MIME data
of the drop event is:
application/x-qt-windows-mime;value="Shell IDList Array"
This is a Windows format with an array of PIDLs which is not exactly
what I would like to deal with. Is there any way to obtain the path and
name of the file in a non-platform-specific way? It feels like I am
making an easy thing into something complicated here.
Best Regards,
Daniel Hedberg
--
To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with
"unsubscribe" in the subject or the body.
List archive and information: http://lists.trolltech.com/qt-interest/
--
[ signature omitted ]
Message 9 in thread
Paulo J. Matos schrieb:
> Hello all,
>
> I have an application using sqlite, however, in the first run I need
> to create the database tables and initialize some other stuff. How can
> I check if it is the first run or not, i.e. if I need to call the
> function for table creation?
How about QFile::exists()? Or a flag in QSettings?
Martin
--
[ signature omitted ]
Message 10 in thread
On 5/14/07, Martin Gebert <Martin.Gebert@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Paulo J. Matos schrieb:
> > Hello all,
> >
> > I have an application using sqlite, however, in the first run I need
> > to create the database tables and initialize some other stuff. How can
> > I check if it is the first run or not, i.e. if I need to call the
> > function for table creation?
>
> How about QFile::exists()?
File? But I never create a file in sqlite... It's the first time I'm
using sqlite, am I missing something? Even when using Qt I never
create a file, I have a name for the DB, I create and manage it.
Nothing else!
> Or a flag in QSettings?
That's a possibility.
Thank you!
>
> Martin
>
> --
> To mail me in private, please remove the -NOSPAM- part from the address
> above.
>
> Ultimate Truths in software development # 5:
> If it ain't broken, don't fix it.
>
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
>
>
>
>
--
[ signature omitted ]
Message 11 in thread
Paulo J. Matos schrieb:
>> > I have an application using sqlite, however, in the first run I need
>> > to create the database tables [...]
>>
>> How about QFile::exists()?
>
> File? But I never create a file in sqlite... It's the first time I'm
> using sqlite, am I missing something? Even when using Qt I never
> create a file, I have a name for the DB, I create and manage it.
> Nothing else!
Well, then, where does SQLite store your data permanently?
Yes, I think you're missing the particularities SQLite. You may want to read
http://www.sqlite.org/different.html
esp. section "Single Database File", and
http://www.sqlite.org/capi3ref.html#sqlite3_open
Martin
--
[ signature omitted ]
Message 12 in thread
As an afterthought: Checking for the DB file isn't portable to other
DBMS, as Nikolays solution is, and using a DBMS independent solution
would be cleaner, of course. However, it wouldn't hurt to know the
idiosyncrasies of the DBMS you're writing your software for in the first
place... ;-)
Martin
--
[ signature omitted ]
Message 13 in thread
On 5/14/07, Martin Gebert <Martin.Gebert@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Paulo J. Matos schrieb:
> >> > I have an application using sqlite, however, in the first run I need
> >> > to create the database tables [...]
> >>
> >> How about QFile::exists()?
> >
> > File? But I never create a file in sqlite... It's the first time I'm
> > using sqlite, am I missing something? Even when using Qt I never
> > create a file, I have a name for the DB, I create and manage it.
> > Nothing else!
>
> Well, then, where does SQLite store your data permanently?
> Yes, I think you're missing the particularities SQLite. You may want to read
> http://www.sqlite.org/different.html
> esp. section "Single Database File", and
> http://www.sqlite.org/capi3ref.html#sqlite3_open
>
But Qt doesn't ask for a path. So does it store the file in any
special default place?
> Martin
>
> --
> To mail me in private, please remove the -NOSPAM- part from the address
> above.
>
> Ultimate Truths in software development # 4:
> DRY
>
> --
> To unsubscribe - send a mail to qt-interest-request@xxxxxxxxxxxxx with "unsubscribe" in the subject or the body.
> List archive and information: http://lists.trolltech.com/qt-interest/
>
>
>
>
--
[ signature omitted ]
Message 14 in thread
Hi,
> But Qt doesn't ask for a path. So does it store the file in any
> special default place?
I think the documentation isn't very clear:
http://doc.trolltech.com/4.2/qsqldatabase.html#setDatabaseName
There's a paragraph about Microsoft Access:
For example, Microsoft Access users can use the following
connection string to open an .mdb file directly, instead
of having to create a DSN entry in the ODBC manager:
...
db = QSqlDatabase::addDatabase("QODBC");
db.setDatabaseName("DRIVER={Microsoft Access Driver (*.mdb)};
FIL={MS Access};DBQ=myaccessfile.mdb");
if (db.open()) {
// success!
}
...
but unfortunately nothing relating to SQLite.
The database name is used to create a file that contains a file the SQLite
database. If you provide a name such as "foo" without a full path, my guess is
that the database will be created in a file "foo" in the current directory,
which isn't a very good idea. I didn't look at the source code of Qt, so this
is just a guess.
--
[ signature omitted ]
Message 15 in thread
> The database name is used to create a file that contains a file the
> SQLite database. If you provide a name such as "foo" without a full
> path, my guess is that the database will be created in a file "foo" in
> the current directory, which isn't a very good idea. I didn't look at
> the source code of Qt, so this is just a guess.
That's correct, IIRC. Better specify a path to avoid unwanted surprises.
See the docs in
doc/html/sql-driver.html#qsqlite-for-sqlite-version-3-and-above:
'SQLite operates on a single file, which must be set as the database
name when opening a connection. If the file does not exist, SQLite will
try to create it. SQLite also supports in-memory databases, simply pass
":memory:" as the database name.'
Martin
--
[ signature omitted ]
Pages: Prev | 1 | 2 | Next
