Selecting data from a database without using SQL statements in Qt

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Article Metadata

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Tested with

Devices(s): Nokia 5800 XpressMusic, Nokia N900

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Compatibility

Platform(s): Qt

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Article

Keywords: QSqlTableModel

Created: tepaa (09 Sep 2009)

Last edited: hamishwillee (11 Oct 2012)

Overview

This example shows how to select data with QSqlTableModel from an SQLite database in Qt without using any SQL statements.

The table 'person' has the following columns:

• id (integer primary key), this is an auto-increment field
• firstname (varchar(20))
• lastname (varchar(30))
• age (integer)

Preconditions

Download and install the Qt SDK

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

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

Header

#include <QSqlTableModel>
#include <QSqlRecord>
#include <QString>

Source

Select person data. The person ID is given as a filter for the selection.

QString MyWidget::searchPersonName(int personId)
    {
    QString name;    
    QSqlTableModel *model = new QSqlTableModel;
    // Set used table
    model->setTable("person");
    model->setEditStrategy(QSqlTableModel::OnManualSubmit);
    // Set where clause
    model->setFilter(QString("id=%1").arg(personId));
    model->select();
 
    //The index of the record we are interested in
    int index = 0; 
 
    // Read result
    QSqlRecord record = model->record(index);
    if (!record.isEmpty())
        name = record.value(2).toString();
    return name;
    }

Postconditions

The person's data is selected from the database without using SQL statements.

See also

• Creating an SQLite database in Qt
• 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
• Using QDataWidgetMapper to show data from a database in Qt
• QtSql module