Selecting data from a database without using SQL statements in Qt
Article Metadata
Tested with
Devices(s): Nokia 5800 XpressMusic, Nokia N900
Compatibility
Platform(s): Qt
Article
Keywords: QSqlTableModel
Created: tepaa
(09 Sep 2009)
Last edited: hamishwillee
(11 Oct 2012)
Contents |
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.
