Refresh QDataTable

[shamik]

main.cpp is as under :

#include <qapplication.h>
#include "loginfrm.h"
#include "editfrm.h"
#include<qsqldatabase.h>
#include<qstring.h>
#include <qthread.h>
#include <stdlib.h>
#include <qwidget.h>
#include <qtimer.h>
 
int main( int argc, char **argv )
{
    QApplication a( argc, argv );
    QSqlDatabase *db = QSqlDatabase::addDatabase("QMYSQL3");
    db->setDatabaseName("logindb");
    db->setUserName("root");
    db->setPassword("");
    db->setHostName("localhost");
    db->open();    
    if ( !db->open())
    {
	qWarning(" database connection no thayu ");
    }
 
    editfrm efrm;
 
    a.setMainWidget( &efrm );
 
    efrm.show();
    qWarning("waiting for login");
    qWarning("creating timer");
    QTimer *timer = new QTimer( &efrm , "mt" );
    efrm.connect( timer, SIGNAL(timeout()), SLOT(refreshTable()) );
    timer->start( 5000, FALSE ); /* 3 seconds single-shot timer 3000 */
    a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit()   ) );
 
    qWarning("Leaving main");
    return a.exec();
 
}

#include <qapplication.h>
#include "loginfrm.h"
#include "editfrm.h"
#include<qsqldatabase.h>
#include<qstring.h>
#include <qthread.h>
#include <stdlib.h>
#include <qwidget.h>
#include <qtimer.h>
	
int main( int argc, char **argv )
{
    QApplication a( argc, argv );
    QSqlDatabase *db = QSqlDatabase::addDatabase("QMYSQL3");
    db->setDatabaseName("logindb");
    db->setUserName("root");
    db->setPassword("");
    db->setHostName("localhost");
    db->open();    
    if ( !db->open())
    {
	qWarning(" database connection no thayu ");
    }
    
    editfrm efrm;
    
    a.setMainWidget( &efrm );

    efrm.show();
    qWarning("waiting for login");
    qWarning("creating timer");
    QTimer *timer = new QTimer( &efrm , "mt" );
    efrm.connect( timer, SIGNAL(timeout()), SLOT(refreshTable()) );
    timer->start( 5000, FALSE ); /* 3 seconds single-shot timer 3000 */
    a.connect( &a, SIGNAL( lastWindowClosed() ), &a, SLOT( quit()   ) );
	
    qWarning("Leaving main");
    return a.exec();
    
}

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NOTE : the editfrm gets some of its values from loginfrm because it is loaded first. but for the ease of understanding i have directly called editfrm from the main. It might be incorrect from the implementation point of view but it is absolutely correct logically. The loginfrm does nothing but initializes some global variables so that editfrm can use it. In the actual code the loginfrm is loaded first and then if the login is correct then the editfrm is loaded. It is only here that i have changed main function to show() the editfrm directly.

editfrm.ui.h is as follows :

#include<qapplication.h>
#include<qsqldatabase.h>
#include "loginfrm.h"
#include "modifyfrm.h"
#include <qwidget.h>
#include<qdatatable.h>
#include <qtimer.h>
#include<qthread.h>
#include <qobject.h>
#include <qtable.h>
#include <qsqlcursor.h>
 
static int btn;
static int i=0;
 
void editfrm::initvalues()
{
 
    loginfrm *lfrm = new loginfrm();
 
    if ( lfrm->check())
    {	
	PB_add->setEnabled(TRUE);
	PB_edit->setEnabled(TRUE);
	PB_delete->setEnabled(TRUE);
    }
    else
    {	
	PB_add->setEnabled(FALSE);
	PB_edit->setEnabled(FALSE);
	PB_delete->setEnabled(FALSE);	
    }   
 
}
 
 
void editfrm::addclicked()
{
    btn=1;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues();    
    hide();
    mfrm->show();    
}
 
 
void editfrm::editclicked()
{
 
    btn=2;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues(); 
    hide();
    mfrm->show();    
}
 
 
void editfrm::deleteclicked()
{
    btn=3;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues(); 
    hide();
    mfrm->show();    
}
 
int editfrm::checkbtn()
{
    return btn;
}
 
void editfrm::cancelclicked()
{	
    loginfrm *lfrm = new loginfrm(this);
    hide();
    lfrm->show();    
}
 
void editfrm::refreshTable()
{    
    QString swar="";
    swar.sprintf("tick tick %d",i);
    qWarning(swar);
    dataTable1->update();
    dataTable1->repaint(true);
    dataTable1->refresh(QDataTable::RefreshAll);
    update();
    i++;
}

#include<qapplication.h>
#include<qsqldatabase.h>
#include "loginfrm.h"
#include "modifyfrm.h"
#include <qwidget.h>
#include<qdatatable.h>
#include <qtimer.h>
#include<qthread.h>
#include <qobject.h>
#include <qtable.h>
#include <qsqlcursor.h>

static int btn;
static int i=0;

void editfrm::initvalues()
{
    
    loginfrm *lfrm = new loginfrm();
    
    if ( lfrm->check())
    {	
	PB_add->setEnabled(TRUE);
	PB_edit->setEnabled(TRUE);
	PB_delete->setEnabled(TRUE);
    }
    else
    {	
	PB_add->setEnabled(FALSE);
	PB_edit->setEnabled(FALSE);
	PB_delete->setEnabled(FALSE);	
    }   
    
}


void editfrm::addclicked()
{
    btn=1;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues();    
    hide();
    mfrm->show();    
}


void editfrm::editclicked()
{

    btn=2;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues(); 
    hide();
    mfrm->show();    
}


void editfrm::deleteclicked()
{
    btn=3;
    modifyfrm *mfrm = new modifyfrm();
    mfrm->initvalues(); 
    hide();
    mfrm->show();    
}

int editfrm::checkbtn()
{
    return btn;
}

void editfrm::cancelclicked()
{	
    loginfrm *lfrm = new loginfrm(this);
    hide();
    lfrm->show();    
}

void editfrm::refreshTable()
{    
    QString swar="";
    swar.sprintf("tick tick %d",i);
    qWarning(swar);
    dataTable1->update();
    dataTable1->repaint(true);
    dataTable1->refresh(QDataTable::RefreshAll);
    update();
    i++;
}

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as per the timer after every 3 secs "tick tick i " is printed but the datatable is not getting updated or refreshed.
as u can see i have tried out with update(), repaint(), refresh(), none of which is working here. the datatable is failing to show the updated database. The database is getting updated from another GUI which is out of this project. I simultaneously run both the project 's GUI and after making changes in the database from one GUI in one project it doesnt get showed in the GUI of another project.

i hope atleast now the picture is very much clear.
please help me solve this problem

thanks and regards
shamik

[jacek]

I simultaneously run both the project 's GUI and after making changes in the database from one GUI in one project it doesnt get showed in the GUI of another project.

Can you see those changes if you connect to the database using a SQL console?

[shamik]

Can you see those changes if you connect to the database using a SQL console?

what do you mean by this SQL console? how to start it??

[jacek]

what do you mean by this SQL console? how to start it??

It's a program that allows you to issue SQL queries to the database server. AFAIR MySQL calls it "mysql".

[shamik]

i opened the console and typed mysql
then mysql prompt appeared. do you mean this as mysql console??

now i typed the select query on that particular table. now the table is shown on the console.
keeping that open, i ran the exe of the project through which i want to change the database content. i made the changes from its GUI. but the sql table in the console showed the same result (it is obvious). to see the changes i have to write the query in the console again. then i can see the changes.

this is the case with the original project too. the qdatatable widget doesnt reflect the changes as it should be. but whenever i hide it and show other dialog and then again i hide the second dialog and show the original dialog with qdatatable widget then i can see the changes. (hiding and showing is implemented with the help of necessary functions inside the code like show(), hide() ).


if u call opening mysql from console which gives u mysql prompt like this-->
mysql>

then it is obvious that it wil show the changes in the database only if u write the query again after changing it from the GUI.

if u r talking of any other MYSQL console then please tell me how to open it and how to work on it. i'll try on that also.

[jacek]

but whenever i hide it and show other dialog and then again i hide the second dialog and show the original dialog with qdatatable widget then i can see the changes. (hiding and showing is implemented with the help of necessary functions inside the code like show(), hide() ).

Can you see the changes if you keep that QDataTable shown for more than 5 seconds (i.e. long enough for the timer to emit the signal)?

[shamik]

no.

no changes are seen in the qdatatable no matter howlong i keep the timer going on

[sunil.thaha]

It might be possible that the changes you make to the database from the client are not commited !!

So, You can try comitting the changes to database.
One more thing, Hope you are setting the interval as 3000 for 3 Sec

[shamik]

i have treid commiting the database after every record change but still it isnt working. the timer time can b anything, may be 3, 5, 7 sec etc. that is not a problem.
after the database is changed the timer may go on to even ticking 40 times still there is no change in the QDataTable.

even if the QDataTable is kept shown for say 5 mins then also there is no change in it. i.e. the updated values are not shown.

is there anything that v m missing ? i donno why does this simple one takes too much of time.
please help me

[jacek]

Can you see the changes if you update your database using the console (i.e. "mysql" program)?

[shamik]

No
cant see the changes in the QDataTable even if i change the database from mysql prompt :
mysql>

i dont understand what is the problems.??

[jacek]

Do you start any transactions before reading data from the database?