qt how to connect to sqlite db file

[TomASS]

Hello, I have a sqlite db file, it name is "tomek.sqlite". In this db I have a one table name: "am_tankowania"

In code, I put:

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
 
    db.setDatabaseName("tomek.sqlite");
    if(db.open()) QMessageBox::information(0,"Ok","Connection ok");
    else QMessageBox::information(0,"Error","some error.");

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");

    db.setDatabaseName("tomek.sqlite");
    if(db.open()) QMessageBox::information(0,"Ok","Connection ok");
    else QMessageBox::information(0,"Error","some error.");

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The MessageBox ok - connection ok show. Now, I have a query:

select * from am_tankowania:

QSqlQuery query("SELECT * am_tankowania");
 if (query.lastError().isValid()) QMessageBox::critical(0,"Error",query.lastError().text() );

QSqlQuery query("SELECT * am_tankowania");
 if (query.lastError().isValid()) QMessageBox::critical(0,"Error",query.lastError().text() );

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I see an error:
no such table table: am_tankowania Unable to execute statement :/

What i'm doing wrong?

Thank you.