Cannot display the data from SQLITE in tableView

drich

Hello I create a program that will display my data from SQLITE to tableView. I dont get any error when I run it but when I click the load button it doesn't show the data.

here is my code:
from mainwindow.h

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    QSqlDatabase mydb;

    void connClose()
    {
    mydb.close();
    mydb.removeDatabase(QSqlDatabase::defaultConnection);
    }
    bool connOpen()
    {
      QSqlDatabase mydb=QSqlDatabase::addDatabase("QSQLITE");
        mydb.setDatabaseName("C:/User/Desktop/GUI/CIMS/Cow DIrectory.db");

        if (!mydb.open()){
            qDebug()<<("Failed to open the database");
          return false;
        }
        else{
           qDebug()<<("Connected. . . .");
           return true;
        }
    }
from mainwindow.cpp
```MainWindow::MainWindow(QMainWindow *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    mydb=QSqlDatabase::addDatabase("QSQLITE");
    mydb.setDatabaseName("C:/Users/Desktop/GUI/CIMS/Cow DIrectory.db");

    if (!mydb.open())
        ui->label_sql->setText("Failed to open the database");
    else
        ui->label_sql->setText("Connected. . . .");

}

MainWindow::~MainWindow()
{
    delete ui;

}
void MainWindow::on_pushButton_load_clicked()
{
   MainWindow conn;
   QSqlQueryModel *modal=new QSqlQueryModel();

   conn.connOpen();
   QSqlQuery* qry=new QSqlQuery(conn.mydb);

   qry->prepare("Select * from main");

   qry->exec();
   modal->setQuery(*qry);
   ui->tableView_cowdirectory->setModel(modal);

   conn.connClose();
   qDebug()<<(modal->rowCount());
}

and I get this when I click the load button.
QSqlDatabasePrivate::removeDatabase: connection 'qt_sql_default_connection' is still in use, all queries will cease to work.
QSqlDatabasePrivate::addDatabase: duplicate connection name 'qt_sql_default_connection', old connection removed.
QSqlDatabasePrivate::removeDatabase: connection 'qt_sql_default_connection' is still in use, all queries will cease to work.
QSqlDatabasePrivate::addDatabase: duplicate connection name 'qt_sql_default_connection', old connection removed.
Failed to open the database
QSqlQuery::prepare: database not open
0
get_accChild got a negative varChildID (-14), but did not find it in cache
get_accChild got a negative varChildID (-19), but did not find it in cache

artwaw

Hi,
you do not need qry here, you can just do modal->setQuery("select * from main;");
Also, I would swap modal->setQuery(); line with the next one: first assign model to a view, then set query - once you set a query on this model it gets populated with data and the view should reflect that.

jsulm

@drich Why do you open your database twice? Once in bool connOpen() and once in MainWindow::MainWindow(QMainWindow *parent). It is enough to open it only once...

drich

Thank you, I already figure it out last night. :)