Getting error when saving file from QML to Sqlite. Error like this =>Property 'saveToSqlite' of object QObject(0x7ffcfa692910) is not a function

Pappu Kumar Keshari

My Full code is =>

dbmanager.h file==>

#ifndef DBMANAGER_H
#define DBMANAGER_H
#include <QObject>
#include <QSqlDatabase>

/**

\class DbManager
\brief SQL Database Manager class
DbManager sets up the connection with SQL database
and performs some basics queries. The class requires
existing SQL database. You can create it with sqlite:
1. $ sqlite3 people.db
1. sqilte> CREATE TABLE people(ids integer primary key, name text);
1. sqlite> .quit
  */
  class DbManager : public QObject
  {
  // Q_OBJECT
  public:
  explicit DbManager(QObject *parent = nullptr);
/**
- @brief Constructor
- Constructor sets up connection with db and opens it
- @param path - absolute path to db file
  */
  DbManager(const QString& path);
/**
- @brief Destructor
- Close the db connection
  */
  ~DbManager();
bool isOpen() const;

/**
- @brief Creates a new 'people' table if it doesn't already exist
- @return true - 'people' table created successfully, false - table not created
  */
  bool createTable();
/**
- @brief Add person data to db
- @param name - name of person to add
- @return true - person added successfully, false - person not added
  */
bool addRecord(const QString &name, const QString &fatherName,
const QString &motherName, const QString &mobileNumber,
const QString &selectedGender, const QString &qualification,
const QString &skills, const QString &state,
const QString &city, const QString &landmark,
const QString &pincode);

/**
- @brief Remove person data from db
- @param name - name of person to remove.
- @return true - person removed successfully, false - person not removed
  */
  bool removeRecord(const QString& name);
/**
- @brief Check if person of name "name" exists in db
- @param name - name of person to check.
- @return true - person exists, false - person does not exist
  */
  bool recordExists(const QString& name) const;
/**
- @brief Print names of all persons in db
  */
  void printAllRecords() const;
/**
- @brief Remove all persons from db
- @return true - all persons removed successfully, false - not removed
  */
  bool removeAllRecords();

public slots:

//It will Save Data From QML UI to Sqlite
Q_INVOKABLE bool saveToSqlite(const QString &data);

private:
QSqlDatabase m_db;
};

#endif // DBMANAGER_H

filehandler.h file==>

#ifndef FILEHANDLER_H
#define FILEHANDLER_H

#include <QObject>
#include <QSqlDatabase>

class FileHandler : public QObject
{
Q_OBJECT
public:
explicit FileHandler(QObject *parent = nullptr);

/*Constructor sets up connection with db and opens it
 path - absolute path to db file*/

FileHandler(const QString& path);

public slots:
//It will Save Data From QML UI to File
Q_INVOKABLE bool saveToFile(const QString &data);

private:
QSqlDatabase m_db;
};

#endif // FILEHANDLER_H

========================================
dbmanager.cpp file==>

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

#include <QSqlQuery>
#include <QSqlError>
#include <QSqlRecord>

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 !!!";
}

}

DbManager::~DbManager()
{
if (m_db.isOpen())
{
m_db.close();
}
}

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

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

QSqlQuery query;

query.prepare("CREATE TABLE  student1 (id INTEGER PRIMARY KEY, name TEXT, fatherName TEXT, motherName TEXT, mobileNumber TEXT, gender TEXT, qualification TEXT, skills TEXT, state TEXT, city TEXT, landmark TEXT, pincode TEXT)");
if (!query.exec())
{
    qDebug() << "Couldn't create the table 'student1': one might already exist.";
    success = false;
}

return success;

}

bool DbManager::addRecord(const QString &name, const QString &fatherName,
const QString &motherName, const QString &mobileNumber,
const QString &selectedGender, const QString &qualification,
const QString &skills, const QString &state,
const QString &city, const QString &landmark,
const QString &pincode)
{
if (isOpen())
{
QSqlQuery queryAdd;
queryAdd.prepare("INSERT INTO student1 (name, fatherName, motherName, mobileNumber, gender, qualification, skills, state, city, landmark, pincode) "
"VALUES (:name, :fatherName, :motherName, :mobileNumber, :gender, :qualification, :skills, :state, :city, :landmark, :pincode)");
queryAdd.bindValue(":name", name);
queryAdd.bindValue(":fatherName", fatherName);
queryAdd.bindValue(":motherName", motherName);
queryAdd.bindValue(":mobileNumber", mobileNumber);
queryAdd.bindValue(":gender", selectedGender);
queryAdd.bindValue(":qualification", qualification);
queryAdd.bindValue(":skills", skills);
queryAdd.bindValue(":state", state);
queryAdd.bindValue(":city", city);
queryAdd.bindValue(":landmark", landmark);
queryAdd.bindValue(":pincode", pincode);

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

return false;

}

bool DbManager::removeRecord(const QString& name)
{
bool success = false;

if (recordExists(name))
{
    QSqlQuery queryDelete;
    queryDelete.prepare("DELETE FROM people WHERE name = (:name)");     
    queryDelete.bindValue(":name", name);
    success = queryDelete.exec();

    if(!success)
    {
        qDebug() << "remove person failed: " << queryDelete.lastError();
    }
}
else
{
    qDebug() << "remove person failed: person doesnt exist";
}

return success;

}

void DbManager::printAllRecords() const
{
qDebug() << "Persons in Database:";
QSqlQuery query("SELECT * FROM student1");

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();
    QString mobileNumber = query.value("mobileNumber").toString();
    QString selectedGender = query.value("gender").toString();
    QString qualification = query.value("qualification").toString();
    QString skills = query.value("skills").toString();
    QString state = query.value("state").toString();
    QString city = query.value("city").toString();
    QString landmark = query.value("landmark").toString();
    QString pincode = query.value("pincode").toString();

    qDebug() << "Name: " << name;
    qDebug() << "Father's Name: " << fatherName;
    qDebug() << "Mother's Name: " << motherName;
    qDebug() << "Mobile Number: " << mobileNumber;
    qDebug() << "Gender: " << selectedGender;
    qDebug() << "Qualification: " << qualification;
    qDebug() << "Skills: " << skills;
    qDebug() << "State: " << state;
    qDebug() << "City: " << city;
    qDebug() << "Landmark: " << landmark;
    qDebug() << "Pincode: " << pincode;
}

}

bool DbManager::recordExists(const QString& name) const
{
bool exists = false;

QSqlQuery checkQuery;
checkQuery.prepare("SELECT name FROM people WHERE name = (:name)");              ///////////////////////////////////////
checkQuery.bindValue(":name", name);

if (checkQuery.exec())
{
    if (checkQuery.next())
    {
        exists = true;
    }
}
else
{
    qDebug() << "person exists failed: " << checkQuery.lastError();
}

return exists;

}

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

QSqlQuery removeQuery;
removeQuery.prepare("DELETE FROM people");

if (removeQuery.exec())
{
    success = true;
}
else
{
    qDebug() << "remove all persons failed: " << removeQuery.lastError();
}

return success;

}

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

addRecord(list.at(0),list.at(1),list.at(2),list.at(3),list.at(4),list.at(5),list.at(6),list.at(7)
          ,list.at(8),list.at(9),list.at(10));

printAllRecords();

}

========================================
filehandler.cpp file==>

#include "filehandler.h"
#include <QFile>
#include <QTextStream>
#include <QDateTime>
#include <QDebug>

#include <QSqlQuery>
#include <QSqlError>
#include <QSqlRecord>

FileHandler::FileHandler(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 !!!";
}

}

FileHandler::FileHandler(QObject *parent) : QObject(parent){}
bool FileHandler::saveToFile(const QString &data)
{
QString fileName = QDateTime::currentDateTime().toString("dd-mm-yyyy-hh:mm:ss");
fileName +=".txt";

QFile file("/root/Desktop/"+fileName);
if(!file.open(QIODevice::WriteOnly | QIODevice::Text))

    return false;

QTextStream stream(&file);
stream << data;
file.close();

return true;

}

========================================

main.cpp file ==>

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <filehandler.h>
#include <dbmanager.h>
static const QString path = "example.db";

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

DbManager dbManager(path); //

engine.rootContext()->setContextProperty("file_Handler", &fileHandler);

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

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

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

return app.exec();

}

========================================
main.qml file==>

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: 700
visible: true
title: qsTr("Student Login Form")
flags: Qt.SplashScreen | Qt.FramelessWindowHint

property string name: ""
property string fatherName: ""
property string motherName: ""
property string mobileNumber: ""
property string rajya: ""
property string city: ""
property string landMark: ""
property string pinCode: ""
property var selectedItems: []
property string selectedGender: ""

//Top Heading
Rectangle{
    id:containerRect
    y: 0
    height: 44
    anchors.left:  parent.left
    anchors.right: parent.right
    anchors.leftMargin: 0
    anchors.rightMargin: 0
    color: "dodgerblue"
    border.color: "#000000"
    border.width: 6

    //Heading Name
    Text{
        width: 245
        height: 29
        anchors.centerIn: parent
        text: "Student Login Form"
        font.family: "Times New Roman"
        anchors.verticalCenterOffset: -5
        anchors.horizontalCenterOffset: 3
        color: "#fefff6"
        font.pointSize: 20
    }

    Button {
        id: button1
        x: 389
        y: 8
        width: 98
        height: 26
        text: qsTr("Close")
        font.bold: true
        MouseArea{
            anchors.fill: parent
            onClicked: {
                Qt.quit();
            }

            Rectangle{
                anchors.centerIn:parent
                width: 98
                height: 26
                radius: 2
                color: "red"
            }
        }
    }
}

Rectangle{

    id:containerRect1
    color: "#f1ffffff"
    radius: 6
    border.color: "#f797187f"
    border.width: 2
    anchors.fill: parent
    anchors.rightMargin: 8
    anchors.bottomMargin: 23
    anchors.leftMargin: 9
    anchors.topMargin: 53

    GroupBox {
        id: groupBox
        height: 312
        anchors.left: parent.left
        anchors.right: parent.right
        anchors.top: parent.top
        anchors.bottomMargin: -1
        layer.textureSize.width: 4
        anchors.rightMargin: 15
        anchors.leftMargin: 11
        anchors.topMargin: 2
        title: qsTr("Personal Details")

        Label  {
            id: label
            x: 50
            y: 17
            text: qsTr("Name")
        }

        Label {
            id: label1
            x: 50
            y: 47
            text: qsTr("Father's Name")
            rotation: -1.907
        }

        Label {
            id: label2
            x: 50
            y: 81
            text: qsTr("Mother's Name")
        }

        Label {
            id: label3
            x: 50
            y: 123
            text: qsTr("Mobile Number")
        }

        Label {
            id: label4
            x: 50
            y: 164
            width: 49
            height: 30
            text: qsTr("Gender")
        }

        Label {
            id: label5
            x: 50
            y: 211
            text: qsTr("Qualification")
        }

        TextField {
            id: nameTextField
            x: 175
            y: 8
            width: 238
            height: 29
            text: "Pappu"
            placeholderText: qsTr("Enter your name")
            onTextChanged: name=text
        }

        TextField {
            id: fatherNameTextField
            x: 175
            y: 44
            width: 238
            height: 29
            text: "Father Name"
            placeholderText: qsTr("Enter your Father's name ")
            onTextChanged: fatherName=text
        }

        TextField {
            id: motherNameTextField
            x: 175
            y: 81
            width: 238
            height: 29
            text: "Mother name"
            placeholderText: qsTr("Enter your Mother's name ")
            onTextChanged: motherName=text
        }

        TextField {
            id: mobileNumberTextField
            x: 175
            y: 123
            width: 238
            height: 29
            text: "85254"
            placeholderText: qsTr("Enter your mobile number")
            onTextChanged: mobileNumber=text
        }

        RowLayout{
            x: 165
            y: 160
            scale: 0.9
            RadioButton{
                text: "Male"
                checked: selectedGender==="Male"
                onClicked: {
                    if(checked) selectedGender="Male"
                }
            }
            RadioButton{
                text: "Female"
                checked: selectedGender==="Female"
                onClicked: {
                    if(checked) selectedGender="Female"
                }
            }
        }

        ComboBox {
            id: comboBox
            x: 178
            y: 206
            width: 140
            height: 30
            model: ["--Select--","10th","12th","Graduation","Post Graduation"]
        }

        Label {
            id: label10
            x: 50
            y: 244
            text: qsTr("Skills")
        }


        Row{
            spacing: 10
            x: 170
            y: 235

            CheckBox {
                id: checkBoxC
                text: qsTr("C")
                checked: true
            }

            CheckBox {
                id: checkBoxCPlusPlus
                text: qsTr("C++")
            }

            CheckBox {
                id: checkBoxQt
                text: qsTr("Qt")
            }
        }

    }

    GroupBox {
        id: groupBox1
        height: 254
        anchors.left: parent.left
        anchors.right: parent.right
        anchors.top: parent.top
        anchors.rightMargin: 13
        anchors.leftMargin: 13
        anchors.topMargin: 314
        title: qsTr("Address")

        Label {
            id: label6
            x: 50
            y: 27
            width: 53
            height: 20
            text: qsTr("State")
        }

        Label {
            id: label7
            x: 50
            y: 72
            width: 50
            height: 20
            text: qsTr("City")
        }

        Label {
            id: label8
            x: 50
            y: 125
            width: 83
            height: 20
            text: qsTr("Land mark")
        }

        Label {
            id: label9
            x: 50
            y: 175
            width: 61
            height: 20
            text: qsTr("Pincode")
        }

        TextField {
            id: stateTextField
            x: 178
            y: 21
            width: 238
            height: 29
            text: "Kar"
            placeholderText: qsTr("Enter your State")
            onTextChanged: rajya=text
        }

        TextField {
            id: cityTextField
            x: 178
            y: 72
            width: 238
            height: 29
            text: "Bang"
            placeholderText: qsTr("Enter your City ")
            onTextChanged:city=text
        }

        TextField {
            id: landmarkTextField
            x: 175
            y: 126
            width: 238
            height: 29
            text: "BEL"
            placeholderText: qsTr("Enter your Landmark ")
            onTextChanged: landMark=text
        }

        TextField {
            id: pincodeTextField
            x: 175
            y: 176
            width: 238
            height: 29
            text: "560013"
            placeholderText: qsTr("Enter your Pincode ")
            onTextChanged: pinCode=text
        }
    }

    Button {
        id: button
        x: 172
        y: 568
        width: 99
        height: 37
        text: qsTr("Submit")
        layer.format: ShaderEffectSource.RGB
        font.weight: Font.Bold
        font.underline: false
        font.strikeout: false
        font.bold: true
        font.family: "Verdana"

        onClicked: {

            //It will show Data From UI to Console
            //                console.log("Name is :",name)
            //                console.log("Father's Name is :",fatherName)
            //                console.log("Mother's Name is :",motherName)
            //                console.log("Mobile Number is :",mobileNumber)
            //                console.log("Gender is :",selectedGender)

            var selectedItem=comboBox.currentText
            var selectedIndex=comboBox.currentIndex
            if(selectedIndex==0)
            {
                //                    console.log("Qualification is :",)
            }
            else
            {
                //                    console.log("Qualification is :",selectedItem)
            }

            selectedItems=[];
            if(checkBoxC.checked)
                selectedItems.push(checkBoxC.text)
            if(checkBoxCPlusPlus.checked)
                selectedItems.push(checkBoxCPlusPlus.text)
            if(checkBoxQt.checked)
                selectedItems.push(checkBoxQt.text)
            //                console.log("Skills :",selectedItems.toString())
            //                console.log("State is :",rajya)
            //                console.log("City is :",city)
            //                console.log("Land Mark is :",landMark)
            //                console.log("Pincode is :",pinCode)


            //Save Data From UI to Text File
            var dataToSave =
                    "Student's Name is : "+ nameTextField.text + "\n" +
                    "Father's Name is : "+ fatherNameTextField.text +"\n"+
                    "Mother's Name is : "+ motherNameTextField.text +"\n"+
                    "Mobile Number is : "+ mobileNumberTextField.text +"\n"+
                    "Gender is : "+ selectedGender +"\n"+
                    "Qualification is : "+ selectedItem.toString() +"\n"+
                    "Skills : "+ selectedItems +"\n"+
                    "State is : "+ stateTextField.text +"\n"+
                    "City is : "+ cityTextField.text +"\n"+
                    "Landmark is : "+ landmarkTextField.text +"\n"+
                    "Pincode is : "+ pincodeTextField.text ;

            if (file_Handler.saveToFile(dataToSave))
            {
                console.log("Data saved to file successfully.");
            }
            else
            {
                console.error("Error saving data to file.");
            }



            //Save Data From UI to Sqlite
            var skillsTxt = selectedItems.join(":").toString();
            var csv_data =
                    nameTextField.text + "," +
                    fatherNameTextField.text +","+
                    motherNameTextField.text +","+
                    mobileNumberTextField.text +","+
                    selectedGender +","+
                    selectedItem+","+
                    skillsTxt +","+
                    stateTextField.text +","+
                    cityTextField.text +","+
                    landmarkTextField.text +","+
                    pincodeTextField.text ;

            if (d_bmmanager.saveToSqlite(csv_data))
            {
                console.log("Data saved to Sqlite successfully.");
            }
            else
            {
                console.error("Error saving data to Sqlite.");
            }


            //It will Reset all field as blank
            nameTextField.text=""
            fatherNameTextField.text=""
            motherNameTextField.text=""
            mobileNumberTextField.text=""
            mobileNumberTextField.text=""
            stateTextField.text=""
            cityTextField.text=""
            landmarkTextField.text=""
            pincodeTextField.text=""

            //When Click on Save Button It will Display message "Data Saved Successfully !!!" and Main window will close
            var messageDialog = Qt.createQmlObject('import QtQuick.Dialogs 1.2; MessageDialog{}',parent);
            messageDialog.text = "Data Saved Successfully !!!";
            messageDialog.standardButtons = StandardButton.Ok;
            messageDialog.accepted.connect(function(){
                //Close the window when "OK" button is clicked
                window.close();
            });
            messageDialog.open();
        }

        Rectangle{
            anchors.centerIn: parent
            width: 99
            height: 37
            color: "green"
            anchors.verticalCenterOffset: 2
            anchors.horizontalCenterOffset: 0
        }
    }
}

}

When above code is running then it is showing error like==>
TypeError: Property 'saveToSqlite' of object QObject(0x7ffe8aee8090) is not a function

========================================
On consile it is showing like this==>
Database Connected Successfully !!!
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.
Database Connected Successfully !!!
qml: Data saved to file successfully.
qrc:/main.qml:433: TypeError: Property 'saveToSqlite' of object QObject(0x7ffe8aee8090) is not a function

SGaist

Hi,

Please use coding tags when posting code. Otherwise it's unreadable.

Next, reduce your code to the bare minimum required to analyse your issue. Remove everything unrelated to your issue. Not many people will be interested in going through that much code with just an error message as entry point.

One thing that is an issue I can see is that you are declaring your invokable function in the slot section of your class. Although related, they are two different things.