@Christian-Ehrlicher, thanks for the guidance. Marking the topic as solved, since a Qt fix is presumably being awaited. Filed a bug report.

@Kofr
If the above snippet works, then you don't respect the SQL's type. You're trying to pass a string representation to Qt when it clearly expects a binary (BLOB is "Binary Large OBject"). So then the question:

How to fix Qt implementation?

comes back as: "How to fix your implementation".
Anyway, I'd suggest passing the appropriate type to the driver. My thoughts are that something like this should be working:

const char rawData[4] = { 0x00, 0x00, 0x00, 0x07 }; QByteArray id = QByteArray::fromRawData(rawData, 4); QSqlQuery query; if (!query.prepare(QStringLiteral("SELECT row FROM %1 WHERE id = :id").arg(tableName))) // Handle the error! query.bindValue(":id", id); // Pass binary data for columns that expect binary if (!query.exec()) // Handle error again!

If you have SQL server why not just create a stored procedure in the server and call it in C++?! It's the best option under all circumstances.

If you can't use that then use a select then use something like:

bool alreadyExist = false; { QSqlQuery query; query.prepare("select * from MyTable where rowID=:rowID"); query.bindValue(":rowID",rowID); if(!query.exec()){ // select failed } alreadyExist = query.next(); } if(alreadyExist){ // update } else{ //insert }

@cxam Hahaha Solved, easily with "query.isActive". Sorry for the stupid question

@SGaist Indeed, you're right When I set the properties for my table I set that the number of rows was "1" so I have to create an "int" variable and then say that the number of rows is that variable starting from 1 and then increment that number on the loop.

@the_ @SGaist Hi, I managed to solve it on my own by encoding the date to a JulianDate and using juliandate on my db so it's much easier to compare and so.

Thanks for your help.

lastQuery should return the actually query that ran against the database, that one would be interesting to see.

Good point of @paul-colby

@mrjj Ok so, it seems that it doesn't detect the table "usuarios" even though it's there...

So in my sqlite editor I executed the command and it worked properly:
http://s18.postimg.org/iqry91pmx/image.png

EDIT: I solved that problem: the program was searching the db in the remote directory not in the real directory, now it doesn't says any error but It doesn't shows the information.

I've tried (SELECT * FROM usuarios) but nothing, it doesn't works.

2ND EDIT: I solved the problem, it was on my printing method, I tried a much simpler methor by doing:

int i=0; while (query.next()) { ui->tableWidget->setItem(i,0,new QTableWidgetItem(query.value(0).toString())); ui->tableWidget->setItem(i,1,new QTableWidgetItem(query.value(1).toString())); ui->tableWidget->setItem(i,2,new QTableWidgetItem(query.value(2).toString())); i++; ui->tableWidget->insertRow(i); }

Thank you for your help.

@mrjj thank you still

Thank you. It worked.

You're setting the wrong role. See my answer here.

https://forum.qt.io/category/10/general-and-desktop -> "New Topic" button

Hi,

Do you mean get additional data using QSqlQuery ?

HI and welcome to devnet,

usually a SELECT statement is in the form SELECT <field_list> FROM <table_name> WHERE <conditions>; in your queries there's no FROM <tablename>.

BTW, QSqlQuery::exec() returns a boolean and you can check the errors with QSqlQuery::lastError()

bool result = query.exec(...); if (!result) { qDebug() << "Error: " << query.lastError().text(); }