When I click on Show Table Button then data should display in Table (TableData.qml) . But Data is not showing in Table .It is showing empty

Pappu Kumar Keshari

dbmanager.h

#ifndef DBMANAGER_H
#define DBMANAGER_H
#include <QObject>
#include <QSqlDatabase>
class DbManager : public QObject
{
    Q_OBJECT
public:
    explicit DbManager(QObject *parent = nullptr);

    DbManager(const QString& path);

    bool isOpen() const;

    bool createTable();

    bool addRecord(const QString &name, const QString &fatherName,const QString &motherName);

    void printAllRecords() const;

    QList<QVariantMap> execQuery(const QString& query);

public slots:

    Q_INVOKABLE bool saveToSqlite(const QString &data);

private:
    QSqlDatabase m_db;
};

#endif // DBMANAGER_H


dbmanager.cpp

#include "dbmanager.h"
#include <QFile>
#include <QTextStream>
#include <QDateTime>
#include <QDebug>
#include <QSqlQuery>
#include <QSqlError>
#include <QSqlRecord>

DbManager::DbManager(QObject *parent) : QObject(parent){}

DbManager::DbManager(const QString &path)
{
    m_db = QSqlDatabase::addDatabase("QSQLITE");
    m_db.setDatabaseName(path);

    if (!m_db.open())
    {
        qDebug() << "Error: connection with database fail";
    }
    else
    {
        qDebug() << "Database Connected Successfully !!!";
    }
    createTable();
}

bool DbManager::isOpen() const
{
    return m_db.isOpen();
}

bool DbManager::createTable()
{
    bool success = false;

    QSqlQuery query;

    query.prepare("CREATE TABLE  student (id INTEGER PRIMARY KEY, name TEXT, fatherName TEXT, motherName TEXT)");
    if (!query.exec())
    {
        qDebug() << "Couldn't create the table 'student': one might already exist.";
        success = false;
    }

    return success;
}

bool DbManager::addRecord(const QString &name, const QString &fatherName, const QString &motherName)
{
    if (isOpen())
    {
        QSqlQuery queryAdd;
        queryAdd.prepare("INSERT INTO student (name, fatherName, motherName) "
                         "VALUES (:name, :fatherName, :motherName)");
        queryAdd.bindValue(":name", name);
        queryAdd.bindValue(":fatherName", fatherName);
        queryAdd.bindValue(":motherName", motherName);

        if (queryAdd.exec())
        {
            return true;
        }
        else
        {
            qDebug() << "Data insertion failed: " << queryAdd.lastError();
        }
    }
    else
    {
        qDebug() << "Database is not open!";
    }

    return false;
}

void DbManager::printAllRecords() const
{
    qDebug() << "Persons in Database:";
    QSqlQuery query("SELECT * FROM student");

    if (!query.exec())
    {
        qDebug() << "Error executing query: " << query.lastError().text();
        return;
    }

    while (query.next())
    {
        QString name = query.value("name").toString();
        QString fatherName = query.value("fatherName").toString();
        QString motherName = query.value("motherName").toString();

        qDebug() << "Name: " << name;
        qDebug() << "Father's Name: " << fatherName;
        qDebug() << "Mother's Name: " << motherName;
    }
}

bool DbManager::saveToSqlite(const QString &data)
{
    QStringList list =data.split(",");
    qDebug()<<"Input Data" <<list;

    addRecord(list.at(0),list.at(1),list.at(2));

    printAllRecords();
}

QList<QVariantMap> DbManager::execQuery(const QString& query)
{
    QList<QVariantMap> results;

    if (isOpen())
    {
        QSqlQuery sqlQuery(query);

        if (sqlQuery.exec())
        {
            while (sqlQuery.next())
            {
                QVariantMap row;
                row["name"] = sqlQuery.value("name").toString();
                row["fatherName"] = sqlQuery.value("fatherName").toString();
                row["motherName"] = sqlQuery.value("motherName").toString();
                results.append(row);
            }
        }
        else
        {
            qDebug() << "Query execution failed: " << sqlQuery.lastError();
        }
    }
    else
    {
        qDebug() << "Database is not open!";
    }

    return results;
}



main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <dbmanager.h>

static const QString path = "example1.db";

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;

    DbManager dbManager(path); //

    engine.rootContext()->setContextProperty("d_bmanager", &dbManager);

    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}


main.qml

import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick.Controls 2.12
import QtQuick.Layouts 1.3
import QtQuick.Dialogs 1.2

Window {
    id: window
    width: 500
    height: 400
    visible: true
    title: qsTr("Student Login Form")

    property string name: ""
    property string fatherName: ""
    property string motherName: ""

    Rectangle{
        Label  {
            x: 50
            y: 25
            text: qsTr("Name")
        }
        Label {
            x: 50
            y: 65
            text: qsTr("Father's Name")
            rotation: -1.907
        }
        Label {
            x: 50
            y: 110
            text: qsTr("Mother's Name")
        }
        TextField {
            id: nameTextField
            x: 175
            y: 25
            width: 238
            height: 29
            placeholderText: qsTr("Enter your name")
            onTextChanged: name=text
        }

        TextField {
            id: fatherNameTextField
            x: 175
            y: 65
            width: 238
            height: 29
            placeholderText: qsTr("Enter your Father's name ")
            onTextChanged: fatherName=text
        }

        TextField {
            id: motherNameTextField
            x: 175
            y: 105
            width: 238
            height: 29
            placeholderText: qsTr("Enter your Mother's name ")
            onTextChanged: motherName=text
        }
    }
    Button {
        id: button
        x: 220
        y: 200
        width: 99
        height: 37
        text: qsTr("Submit")
        onClicked: {
            var csv_data =
                    nameTextField.text + "," +
                    fatherNameTextField.text +","+
                    motherNameTextField.text;
            if (d_bmanager.saveToSqlite(csv_data)){
                console.log("Data saved to Sqlite successfully !!!");
            }
            else{
                console.error("Error While Saving Data to Sqlite.");
            }
        }
    }
    StackView{
        id:stackView
        anchors.fill: parent
    }
    Button {
        id: button2
        x: 350
        y: 200
        width: 99
        height: 37
        text: qsTr("Show Table")
        onClicked: {
            stackView.push(secondPage)
        }
        Component{
            id:secondPage
            TableData{}
        }
    }
}

TableData.qml

import QtQuick 2.7
import QtQuick.Window 2.0
import QtQuick.Controls 1.4

Window
{
    width: 700
    height: 500
    visible: true
    Component.onCompleted: {
        var query = "SELECT * FROM student";
        var result = d_bmanager.execQuery(query);

        for (var i = 0; i < result.length; i++) {
            myModel.append({
                               name: result[i].name,
                               fatherName: result[i].fatherName,
                               motherName: result[i].motherName
                           });
        }
    }
    TableView {
        id: myTable
        anchors.fill: parent
        anchors.margins: 5

        TableViewColumn {
            role: name
            title: "Name"
            width: 250
            horizontalAlignment: Text.AlignHCenter
        }
        TableViewColumn {
            role: fatherName
            title: "Father's Name"
            width: 250
            horizontalAlignment: Text.AlignHCenter
        }
        TableViewColumn {
            role: motherName
            title: "Mother's Name"
            width: 250
            horizontalAlignment: Text.AlignHCenter
        }
    }
}

SGaist

Hi,

Please stop posting the same stuff over and over again and ignoring afterwards.
You already have gotten replies to several of your threads that you did not acknowledge nor replied to. This is slowly but surely getting irritating not to say insulting to the people trying to help.

Pappu Kumar Keshari

@SGaist HI I am not able to get output so I sent whole code. So that anyone can understand my whole code and reply

SGaist

@Pappu-Kumar-Keshari it's your job to reduce your code to the strict minimum. Don't put your whole GUI when one of the core element does not work. Don't put your whole database handler class, just the functions that are currently required. That's all, simplify your code.

By the way, don't keep an instance of QSqlDatabase as member variable. That's not how that class shall be used and you can find why in its documentation.

Pappu Kumar Keshari

@SGaist Hi, Can you please resolve my issue ? I am unable to fetch record from Sqlite to Table in QML. Which time you will be free ? I will share my screen on Zoom then you will get clear idea about my project. It's my humble request to you.

jsulm

@Pappu-Kumar-Keshari Did you actually address what @SGaist told you?
Where is simplified code?
Did you remove QSqlDatabase member variable?
Or do you simply want that somebody fixes your code for free?