[SOLVED] Accessing to an existing SQLite DataBase from Qt

carles.sole.grau

Hi everybody,
I'm trying to read an existing SQLite database from my QML applicattion,
right now, I have the database file imported to my project but I'm unable to acces to it, has somebody knows how to do it?

Thank you very much

p3c0

Hi @carles.sole.grau
Are you getting any specific errors ? Did you open the database from your code?
There's an example which explains it:
http://doc.qt.io/qt-5/qtquick-localstorage-qmlmodule.html

carles.sole.grau

Hi, @p3c0
Yes I looked this example and so far, I know how to create a SQLite database and insert and "read" data from it.

But now, I'm interested in getting information from a external DataBase, so I would like to import it into my projecte to work with it.

Thank you

p3c0

@carles.sole.grau

But now, I'm interested in getting information from a external DataBase, so I would like to import it into my projecte to work with it.

Can you elaborate ?

carles.sole.grau

@p3c0 ,
Sorry for not knowing the meaning, but what exactly are you meaning with "Elaborate"?

p3c0

@carles.sole.grau
Thats fine. Can you give more details of what you are trying to do ?

carles.sole.grau

@p3c0 ,
ups... jaja
Of course,
Right now i have a SQLite database that it has made using SQLite DatabaseBrowser, its extensions is .sqlite.

For my project, I'm interested to have access to this database, to read the content so:
*I add this file to my QML project
*I'm trying to using it using the Javascript functions

But I don't know how to make the program able to read (or to access) to this database.

Thank you

p3c0

@carles.sole.grau Sorry you can't do that using purely js or QML function.s You will need C++ for that. For eg. using QSqlQueryModel.

carles.sole.grau

And any example of that?

Thank you

p3c0

@carles.sole.grau
Here's one:
https://wiki.qt.io/How_to_Use_a_QSqlQueryModel_in_QML

Just needs some minor modifications to make it work with Qt Quick 2.x

carles.sole.grau

Thank you,
I will try it!!

carles.sole.grau

Finally, I could solve my problem, all the things I have had to do are:

In main.cpp I add this code:

QDir dir("./Databases");
if (!dir.exists()) {
    dir.mkpath(".");
}
QString new_name = QString(QCryptographicHash::hash(("nameofthecopiedDB"),QCryptographicHash::Md5).toHex());

QFile file(":/SQLite/nameofsourceDB.sqlite");
file.copy("./Databases/" + new_name + ".sqlite");
file.close();

Since I have the DB I would to use in my project in SQLite folder from my resources (:, indicates resources).
The QCryptographicHash::hash function is necessary because in the:

openDatabaseSync(string name, string version, string description, int estimated_size, jsobject callback(db))

the name is passed with md5 codification: "the path to a database is QQmlEngine::offlineStoragePafh + md5(name) + ".sqlite". Where name is 1st parameter of openDatabaseSync"

And then, in QML file, the openDatabaseSync() function:

db = Sql.LocalStorage.openDatabaseSync('nameofthecopiedDB',"1.0","description",1000000,"QSQLITE")

Thank you!