Need help on QSQLITE

[lam-ang]

Hi,
I'm still new with QT and I have a simple application that add, search and remove records using SQLITE. But everytime I run the application my database is empty. Please check the partial code I'm using.

#include "phonebook.h"
#include "ui_phonebook.h"
#include <QMessageBox>
//./phonebook.db
PhoneBook::PhoneBook(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::PhoneBook)
{
    ui->setupUi(this);
 
    database = new QSqlDatabase();
 
    //set database driver to QSQLITE
    *database = QSqlDatabase::addDatabase("QSQLITE");
    database->setDatabaseName(":memory:");
    //database->setDatabaseName("./phonebook.db");
 
    //can be removed
    database->setHostName("localhost");
    database->setUserName("");
    database->setPassword("");
 
    if(!database->open())
    {
        QMessageBox::warning(0,"Error","Couldn't open database file.");
    }
 
     QSqlQuery query;
     query.exec("CREATE TABLE IF NOT EXISTS Contacts (id int primary key, "
                "name varchar(20), mobile varchar(20),city varchar(20))");
    all_model = new QSqlTableModel(this, *database);
    updateTable();
 
    search_model = new QSqlTableModel(this, *database);
    search_model->setTable("Contacts");
}

#include "phonebook.h"
#include "ui_phonebook.h"
#include <QMessageBox>
//./phonebook.db
PhoneBook::PhoneBook(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::PhoneBook)
{
    ui->setupUi(this);

    database = new QSqlDatabase();

    //set database driver to QSQLITE
    *database = QSqlDatabase::addDatabase("QSQLITE");
    database->setDatabaseName(":memory:");
    //database->setDatabaseName("./phonebook.db");

    //can be removed
    database->setHostName("localhost");
    database->setUserName("");
    database->setPassword("");

    if(!database->open())
    {
        QMessageBox::warning(0,"Error","Couldn't open database file.");
    }

     QSqlQuery query;
     query.exec("CREATE TABLE IF NOT EXISTS Contacts (id int primary key, "
                "name varchar(20), mobile varchar(20),city varchar(20))");
    all_model = new QSqlTableModel(this, *database);
    updateTable();

    search_model = new QSqlTableModel(this, *database);
    search_model->setTable("Contacts");
}

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regards,
lam-ang

[mcosta]

Hi,
I'm still new with QT and I have a simple application that add, search and remove records using SQLITE. But everytime I run the application my database is empty. Please check the partial code I'm using.

The problem is at line 15

database->setDatabaseName(":memory:");

database->setDatabaseName(":memory:");

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you're using a "in memory" SQLITE database.
Comment this line and uncomment the line 16

database->setDatabaseName("./phonebook.db");

database->setDatabaseName("./phonebook.db");

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[lam-ang]

Hi mcosta,
I appreciate the help and the time...I did what you suggested but this give me the output.

Couldn't open database file.

Couldn't open database file.

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is this line means it's creating a database name phonebook or is it only identifying the location of the file?

database->setDatabaseName("./phonebook.db");

database->setDatabaseName("./phonebook.db");

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regards,
lam-ang

[mcosta]

When the database does'n exist, open create it.

Probably you don't have permission to create file in the directory where the program are installed.
Try using your DATA directory.

Use QDesktopServices; for example

QString dbName = QDesktopServices::storageLocation (QDesktopServices::DataLocation) + "/phonebook.db";
database->setDatabaseName(dbName);

QString dbName = QDesktopServices::storageLocation (QDesktopServices::DataLocation) + "/phonebook.db";
database->setDatabaseName(dbName);

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[lam-ang]

Hi,
I tried what you suggested and I added QDesktopService header but I got the same result "Couldn't open database file".

regards,
lam-ang

[mcosta]

Print the Database Driver Message Please

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database.lasteError().text()));
}

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database.lasteError().text()));
}

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[lam-ang]

Print the Database Driver Message Please

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database.lasteError().text()));
}

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database.lasteError().text()));
}

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Hi,
Thanks for the help and the time, but it seems I'm having trouble compiling.

C:\Users\Severpc\Documents\QtFiles1.1\SQLite_example-build-simulator\..\SQLite_example\phonebook.cpp:29: error: request for member 'lasteError' in '((PhoneBook*)this)->PhoneBook::database', which is of non-class type 'QSqlDatabase*'

C:\Users\Severpc\Documents\QtFiles1.1\SQLite_example-build-simulator\..\SQLite_example\phonebook.cpp:29: error: request for member 'lasteError' in '((PhoneBook*)this)->PhoneBook::database', which is of non-class type 'QSqlDatabase*'

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regards,
picuser

[Lykurg]

It's a typo. It has to be lastError().

[mcosta]

It's a typo. It has to be lastError().

I'm sorry!!

[lam-ang]

Hi, I still have errors and would not compile..

:-1: warning: The Symbian tool chain does not handle special characters in the project name 'SQLite_example.pro' well.

:-1: warning: The Symbian tool chain does not handle special characters in the project name 'SQLite_example.pro' well.

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I noticed if I remove this part of code ".arg(database.lasteError().text())" it compiles.

regards,
lam-ang

[mcosta]

The correct code is

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database->lastError().text()));
}

if(!database->open())  {
    QMessageBox::warning(0,"Error",tr("Couldn't open database file: %1").arg(database->lastError().text()));
}

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try it please