Creating an SQLite database in Qt

Comments

Lilian.moraru - Comment

I think that it is important to point out that in order for this to work you should add a new line "QT += sql" in the project file(.pro)

lilian.moraru 01:59, 7 November 2012 (EET)

Hamishwillee - @Lilian - this is a wiki

Hi Lilian

Thanks very much for pointing this out. I added the section. Note that this is a wiki, so if you see changes like this that are worth writing a comment on, then you might as well just add the section :-)

BTW, did you test this on a recent version of Qt, and if so, which one? (this was tested on Qt Tower prerelease, and if you know it works on a later version then that would be great)

hamishwillee 07:47, 7 November 2012 (EET)

Lilian.moraru - Re @Hamishwillee

I tested it on Linux and Windows with Qt version 4.7 and 4.8 and it works.

lilian.moraru 11:11, 7 November 2012 (EET)

Hamishwillee - Thanks very much.

I've added that information in the ArticleMetaData, along with your name as having reviewed it. Also fixed up links to current Qt 4.7 docs.

I think this is closed, so next time I come to this article I'll delete these comments.

Thank you!

hamishwillee 06:25, 8 November 2012 (EET)

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This example shows you how to create an SQLite database in Qt.

Article Metadata

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Tested with

SDK: 4.7 and later (also tested 4.8)

Devices(s): Nokia 5800 XpressMusic, Nokia N900

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Compatibility

Platform(s): Qt

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Article

Keywords: QSqlDatabase, QSQlite, QSqlError

Created: tepaa (24 Nov 2009)

Reviewed: lilian.moraru (08 Nov 2012)

Last edited: hamishwillee (08 Nov 2012)

Preconditions

For Maemo SQLite development, the following packages must be installed:

• libqt4-sql
• libqt4-sql-sqlite
• libsqlite3-0
• libsqlite3-dev

Project file (.pro)

Add the following line to your .pro file

QT += sql

Header

#include <QObject>
#include <QSqlDatabase>
#include <QSqlError>
#include <QFile>
 
class DatabaseManager : public QObject
    {
    public:
        DatabaseManager(QObject *parent = 0);
        ~DatabaseManager();
 
    public:
        bool openDB();
        bool deleteDB();
        QSqlError lastError();
 
    private:
        QSqlDatabase db;
    };

Source

bool DatabaseManager::openDB()
    {
    // Find QSLite driver
    db = QSqlDatabase::addDatabase("QSQLITE");
 
    #ifdef Q_OS_LINUX
    // NOTE: We have to store database file into user home folder in Linux
    QString path(QDir::home().path());
    path.append(QDir::separator()).append("my.db.sqlite");
    path = QDir::toNativeSeparators(path);
    db.setDatabaseName(path);
    #else
    // NOTE: File exists in the application private folder, in Symbian Qt implementation
    db.setDatabaseName("my.db.sqlite");
    #endif
 
    // Open databasee
    return db.open();
    }
 
QSqlError DatabaseManager::lastError()
    {
    // If opening database has failed user can ask 
    // error description by QSqlError::text()
    return db.lastError();
    }
 
bool DatabaseManager::deleteDB()
    {
    // Close database
    db.close();
 
    #ifdef Q_OS_LINUX
    // NOTE: We have to store database file into user home folder in Linux
    QString path(QDir::home().path());
    path.append(QDir::separator()).append("my.db.sqlite");
    path = QDir::toNativeSeparators(path);
    return QFile::remove(path);
    #else
 
    // Remove created database binary file
    return QFile::remove("my.db.sqlite");
    #endif
    }

Postconditions

The database binary file is created on the device disk in Symbian & Windows and in the device memory in Maemo.

See also

• Creating a database table in Qt
• Inserting a row into a database in Qt
• Searching for data in a database in Qt
• Deleting data from a database in Qt
• Selecting data from a database without using SQL statements in Qt
• Using QDataWidgetMapper to show data from a database in Qt

• QtSql module
• Qt QSQlite driver
• SQLite