using an isntance of QSqlDatabase for connection defiinition

[jfinn88]

Thank you for all the help anda_skoa,
Model seems to be working good now I will posted updated code
I'm now wanting to add some functionality to my tableView, Like to be able to search by date and userName... I want to pass text values back to my c++ function a would like to use the signal and slot mechanism to perform this action. However I get lost with what Object I need to pass the QObject::connect() method, for it to work.
I created two signals and two slots one for the date text field in qml and the other is for the userName text field in qml.
in C++ I created to slots to receive the qml signals and to out put the text data passed to the console using a debug() method.
I'm little confused on where to place the QObject::connect method in my project... main.cpp or sqliteModel.cpp in the constructor ?
I am unsure what objects to pass the connect() method for the signal to receive the slot ?
I would also Like to create a table in the database for each separate day for user event logging and delete old tables after 30 days
here is my code: (had to remove functions for model in cpp file to get it to fit)

=========== main.qml===============

import QtQuick 2.5
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.3
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.2
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.4
 
Window {
    signal submitDateText(string text)
    signal submitUserNameText(string text)
    visible: true
    width: 760
    height: 450
    title: "User Event Log"
    TableView {
        width: 750;
        height: 350;
        anchors.centerIn: parent;
        horizontalScrollBarPolicy: 0
        frameVisible: true
        model: sqliteModel
        TableViewColumn {
                role: "id"
                title: "id"
                width: 100
            }
            TableViewColumn {
                role: "userName"
                title: "User Name"
                width: 200
            }
            TableViewColumn {
                role: "eventMessage"
                title: "Event Message"
                width: 200
            }
            TableViewColumn {
                role: "dateTime"
                title: "Date Time"
                width: 200
            }
    }
    RowLayout {
        id: row1
        x: 201
        y: 403
        anchors.horizontalCenter: parent.horizontalCenter;
        anchors.bottom: parent.bottom
        width: 750
        height: 47;
        clip: false
        opacity: 0.9
        Button {
            id: load_btn
            text: qsTr("Load")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    sqliteModel.dbConnect();
                    sqliteModel.sqlSelect();
                }
            }
        }
        Label {
            id: userNameLabel
            text: qsTr("User Name")
        }
        TextField {
            id: userNameTextField
            placeholderText: qsTr("User Name")
        }
        Label {
            id: dateLabel
            width: 39
            height: 17
            text: qsTr("Date")
        }
        TextField {
            id: dateTextField
            width: 125
            height: 25
            placeholderText: qsTr("mm//dd/yyyy")
        }
        Button {
            id: searchBtn
            text: qsTr("Search")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    // emit the submitTextField signal
                    submitDateText(dateTextField.text);
                    submitUserNameText(userNameTextField.text);
                }
            }
        }
        Button {
            id: exit_btn
            text: qsTr("Exit")
            MouseArea{
                anchors.fill: parent
                onClicked: close();
            }
        }
    }
}

import QtQuick 2.5
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.3
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.2
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.4

Window {
    signal submitDateText(string text)
    signal submitUserNameText(string text)
    visible: true
    width: 760
    height: 450
    title: "User Event Log"
    TableView {
        width: 750;
        height: 350;
        anchors.centerIn: parent;
        horizontalScrollBarPolicy: 0
        frameVisible: true
        model: sqliteModel
        TableViewColumn {
                role: "id"
                title: "id"
                width: 100
            }
            TableViewColumn {
                role: "userName"
                title: "User Name"
                width: 200
            }
            TableViewColumn {
                role: "eventMessage"
                title: "Event Message"
                width: 200
            }
            TableViewColumn {
                role: "dateTime"
                title: "Date Time"
                width: 200
            }
    }
    RowLayout {
        id: row1
        x: 201
        y: 403
        anchors.horizontalCenter: parent.horizontalCenter;
        anchors.bottom: parent.bottom
        width: 750
        height: 47;
        clip: false
        opacity: 0.9
        Button {
            id: load_btn
            text: qsTr("Load")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    sqliteModel.dbConnect();
                    sqliteModel.sqlSelect();
                }
            }
        }
        Label {
            id: userNameLabel
            text: qsTr("User Name")
        }
        TextField {
            id: userNameTextField
            placeholderText: qsTr("User Name")
        }
        Label {
            id: dateLabel
            width: 39
            height: 17
            text: qsTr("Date")
        }
        TextField {
            id: dateTextField
            width: 125
            height: 25
            placeholderText: qsTr("mm//dd/yyyy")
        }
        Button {
            id: searchBtn
            text: qsTr("Search")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    // emit the submitTextField signal
                    submitDateText(dateTextField.text);
                    submitUserNameText(userNameTextField.text);
                }
            }
        }
        Button {
            id: exit_btn
            text: qsTr("Exit")
            MouseArea{
                anchors.fill: parent
                onClicked: close();
            }
        }
    }
}

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=========== main.cpp===============

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QSqlDatabase>
#include "sqlitemodel.h"
#include <QUrl>
 
int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    sqliteModel *model = new sqliteModel;
    QQmlApplicationEngine engine;
    QQmlContext *contxt = engine.rootContext();
    contxt->setContextProperty("sqliteModel", model);
    engine.load(QUrl("qrc:/main.qml"));
    return app.exec();
}

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QSqlDatabase>
#include "sqlitemodel.h"
#include <QUrl>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    sqliteModel *model = new sqliteModel;
    QQmlApplicationEngine engine;
    QQmlContext *contxt = engine.rootContext();
    contxt->setContextProperty("sqliteModel", model);
    engine.load(QUrl("qrc:/main.qml"));
    return app.exec();
}

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=========== sqliteModel.cpp==========

#include "sqlitemodel.h"
 
sqliteModel::sqliteModel(QObject *parent):QAbstractListModel(parent)
{
    // connect our QML signal to our C++ slot
    QObject::connect(/*QMLObject(?)*/, SIGNAL(submitDateText(QString)), this, SLOT(searchDateText(QString)));
}
 
sqliteModel::~sqliteModel()
{
}
 
void sqliteModel::createDailyTable()
{
    dbConnect();
    int addOne;
    QSqlQuery createTableQry(m_selectDataBase);
    createTableQry.prepare("CREATE TABLE userlogevents1 AS SELECT * FROM userlogevents WHERE 0");
    createTableQry.exec();
    m_selectDataBase.close();
}
 
void sqliteModel::deleteDailyTable()
{
    dbConnect();
    QSqlQuery selectTables(m_selectDataBase);
    //---Selects all tables older than 30 days in database | Gets date created---//
    selectTables.prepare("SELECT usereventlog, create_date FROM sys.tables WHERE DATEDIFF(day, create_date, getdate()) > 30");
    selectTables.exec();
    QString selectTableResult;
    selectTableResult = selectTables.value(0).toString();
    selectTableResult.append(selectTables.value(1).toString());
    selectTableResult.append(selectTables.value(2).toString());
    qDebug() << selectTableResult;
 
    //--- If the table is older than 30 days drop it---//
        QSqlQuery deleteTableQry(m_selectDataBase);
        deleteTableQry.prepare("DROP TABLE userlogevetns");
        deleteTableQry.exec();
        m_selectDataBase.close();
}
 
void sqliteModel::searchDateFcn(QString dateText)
{
    dbConnect();
    QSqlQuery searchDateQry(m_selectDataBase);
    searchDateQry.prepare("SELECT id, userName, eventMessage, dateTime FROM usereventlog WHERE userName = "+dateText);
    searchDateQry.exec();
    m_selectDataBase.close();
}
 
void sqliteModel::searchUserNameFcn(QString userNameText)
{
    dbConnect();
    QSqlQuery searchDateQry(m_selectDataBase);
    searchDateQry.prepare("SELECT id, userName, eventMessage, dateTime FROM usereventlog WHERE userName = "+ userNameText);
    searchDateQry.exec();
    m_selectDataBase.close();
}
 
void sqliteModel::searchDateText(const QString &dateText)
{
    qDebug() << "c++: sqliteModel::searchDateText:" << dateText;
}
 
void sqliteModel::searchUserNameText(const QString &userNameText)
{
    qDebug() << "c++: sqliteModel::searchUserNameText:" << userNameText;
}

#include "sqlitemodel.h"

sqliteModel::sqliteModel(QObject *parent):QAbstractListModel(parent)
{
    // connect our QML signal to our C++ slot
    QObject::connect(/*QMLObject(?)*/, SIGNAL(submitDateText(QString)), this, SLOT(searchDateText(QString)));
}

sqliteModel::~sqliteModel()
{
}

void sqliteModel::createDailyTable()
{
    dbConnect();
    int addOne;
    QSqlQuery createTableQry(m_selectDataBase);
    createTableQry.prepare("CREATE TABLE userlogevents1 AS SELECT * FROM userlogevents WHERE 0");
    createTableQry.exec();
    m_selectDataBase.close();
}

void sqliteModel::deleteDailyTable()
{
    dbConnect();
    QSqlQuery selectTables(m_selectDataBase);
    //---Selects all tables older than 30 days in database | Gets date created---//
    selectTables.prepare("SELECT usereventlog, create_date FROM sys.tables WHERE DATEDIFF(day, create_date, getdate()) > 30");
    selectTables.exec();
    QString selectTableResult;
    selectTableResult = selectTables.value(0).toString();
    selectTableResult.append(selectTables.value(1).toString());
    selectTableResult.append(selectTables.value(2).toString());
    qDebug() << selectTableResult;

    //--- If the table is older than 30 days drop it---//
        QSqlQuery deleteTableQry(m_selectDataBase);
        deleteTableQry.prepare("DROP TABLE userlogevetns");
        deleteTableQry.exec();
        m_selectDataBase.close();
}

void sqliteModel::searchDateFcn(QString dateText)
{
    dbConnect();
    QSqlQuery searchDateQry(m_selectDataBase);
    searchDateQry.prepare("SELECT id, userName, eventMessage, dateTime FROM usereventlog WHERE userName = "+dateText);
    searchDateQry.exec();
    m_selectDataBase.close();
}

void sqliteModel::searchUserNameFcn(QString userNameText)
{
    dbConnect();
    QSqlQuery searchDateQry(m_selectDataBase);
    searchDateQry.prepare("SELECT id, userName, eventMessage, dateTime FROM usereventlog WHERE userName = "+ userNameText);
    searchDateQry.exec();
    m_selectDataBase.close();
}

void sqliteModel::searchDateText(const QString &dateText)
{
    qDebug() << "c++: sqliteModel::searchDateText:" << dateText;
}

void sqliteModel::searchUserNameText(const QString &userNameText)
{
    qDebug() << "c++: sqliteModel::searchUserNameText:" << userNameText;
}

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=========== sqliteModel.h===============

#ifndef SQLITEMODEL_H
#define SQLITEMODEL_H
 
#include <assert.h>
#include <list>
#include <QList>
#include <QColor>
#include <QObject>
#include <QDebug>
#include <QString>
#include <QFileInfo>
#include <QDateTime>
#include <QQmlError>
#include <QQmlApplicationEngine>
#include <QQmlEngine>
#include <QQmlContext>
#include <QtSql/QSqlDatabase>
#include <QtSql/QSqlQuery>
#include <QtSql/QSqlError>
#include <QtSql/QSqlRecord>
#include <QModelIndex>
#include <QAbstractListModel>
 
struct userEventLogMsg{
  QString id;
  QString username;
  QString eventmessage;
  QString datetime;
};
 
class sqliteModel:public QAbstractListModel
{
    Q_OBJECT
public:
    explicit sqliteModel(QObject *parent = 0);
    ~sqliteModel();
    enum userEventRoles {idRole= Qt::UserRole + 220, nameRole, msgRole, dateRole};
    int rowCount(const QModelIndex & parent) const;
    QHash<int, QByteArray> roleNames() const;
    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const;
    Q_INVOKABLE void addEvent(const userEventLogMsg &msg);
    Q_INVOKABLE void dbConnect();
    Q_INVOKABLE void sqlSelect();
    void createDailyTable();
    void deleteDailyTable();
    void searchDateFcn(QString userDateText);
    void searchUserNameFcn(QString userNameText);
public slots:
    void searchDateText(const QString &dateIn);
    void searchUserNameText(const QString &userNameIn);
private:
    QList<userEventLogMsg> m_msgList;
    QSqlDatabase m_selectDataBase;
    QSqlQuery m_selectQuery;
};

#ifndef SQLITEMODEL_H
#define SQLITEMODEL_H

#include <assert.h>
#include <list>
#include <QList>
#include <QColor>
#include <QObject>
#include <QDebug>
#include <QString>
#include <QFileInfo>
#include <QDateTime>
#include <QQmlError>
#include <QQmlApplicationEngine>
#include <QQmlEngine>
#include <QQmlContext>
#include <QtSql/QSqlDatabase>
#include <QtSql/QSqlQuery>
#include <QtSql/QSqlError>
#include <QtSql/QSqlRecord>
#include <QModelIndex>
#include <QAbstractListModel>

struct userEventLogMsg{
  QString id;
  QString username;
  QString eventmessage;
  QString datetime;
};

class sqliteModel:public QAbstractListModel
{
    Q_OBJECT
public:
    explicit sqliteModel(QObject *parent = 0);
    ~sqliteModel();
    enum userEventRoles {idRole= Qt::UserRole + 220, nameRole, msgRole, dateRole};
    int rowCount(const QModelIndex & parent) const;
    QHash<int, QByteArray> roleNames() const;
    QVariant data(const QModelIndex &index, int role=Qt::DisplayRole) const;
    Q_INVOKABLE void addEvent(const userEventLogMsg &msg);
    Q_INVOKABLE void dbConnect();
    Q_INVOKABLE void sqlSelect();
    void createDailyTable();
    void deleteDailyTable();
    void searchDateFcn(QString userDateText);
    void searchUserNameFcn(QString userNameText);
public slots:
    void searchDateText(const QString &dateIn);
    void searchUserNameText(const QString &userNameIn);
private:
    QList<userEventLogMsg> m_msgList;
    QSqlDatabase m_selectDataBase;
    QSqlQuery m_selectQuery;
};

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I was able to pass the text form qml to my cpp slot by expose Qt slot to QML element. By using the context property I set for my model to be exposed to QML.

now my searchDateText fcn and searchUserName fcn can be called in qml by:

Button {
            id: searchBtn
            text: qsTr("Search")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    sqliteModel.searchDateText(dateTextField.text);
                    sqliteModel.searchUserNameText(userNameTextField.text);
                }
            }
        }

Button {
            id: searchBtn
            text: qsTr("Search")
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    sqliteModel.searchDateText(dateTextField.text);
                    sqliteModel.searchUserNameText(userNameTextField.text);
                }
            }
        }

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(?) I did the same for my dbConnect and sqlSelect fcns however I have to include Q_INVOKABLE when intializing them in the header file or for some reason or I cant call them in QML with out the Q_INVOKABLE keyword but my searchDateText & searchUserNameText fucntions do??? -> error: Property 'dbConnect' of object sqliteModel() is not a function

I would like to pass the QML text using a QML signal to a CPP slot using the QObject::connect() mainly for learning purposes... The objects that I need to pass the connect() method make more sense now, I need to pass a QML object for the qml signal() and pass a class object (sqliteModel) for the slot(), if I use the connect() method in my cpp class (in the constructor) I can use keyword "this" for the CPP object for the connect method?