C++/Qt/Sqlite
Connect to Sqlite and do insert, delete, update and select
<source lang="cpp"> Foundations of Qt Development\Chapter13\sqltest\sqlite\main.cpp /*
* Copyright (c) 2006-2007, Johan Thelin * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of APress nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */
- include <QApplication>
- include <QtSql>
- include <QtDebug>
int main( int argc, char **argv ) {
QApplication app( argc, argv );
QSqlDatabase db = QSqlDatabase::addDatabase( "QSQLITE" );
db.setDatabaseName( "./testdatabase.db" );
if( !db.open() )
{
qDebug() << db.lastError();
qFatal( "Failed to connect." );
}
qDebug( "Connected!" );
QSqlQuery qry;
qry.prepare( "CREATE TABLE IF NOT EXISTS names (id INTEGER UNIQUE PRIMARY KEY, firstname VARCHAR(30), lastname VARCHAR(30))" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug() << "Table created!";
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (1, "John", "Doe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (2, "Jane", "Doe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (3, "James", "Doe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (4, "Judy", "Doe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (5, "Richard", "Roe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (6, "Jane", "Roe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (7, "John", "Noakes")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (8, "Donna", "Doe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "INSERT INTO names (id, firstname, lastname) VALUES (9, "Ralph", "Roe")" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Inserted!" );
qry.prepare( "SELECT * FROM names" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
{
qDebug( "Selected!" );
QSqlRecord rec = qry.record();
int cols = rec.count();
for( int c=0; c<cols; c++ )
qDebug() << QString( "Column %1: %2" ).arg( c ).arg( rec.fieldName(c) );
for( int r=0; qry.next(); r++ )
for( int c=0; c<cols; c++ )
qDebug() << QString( "Row %1, %2: %3" ).arg( r ).arg( rec.fieldName(c) ).arg( qry.value(c).toString() );
}
qry.prepare( "SELECT firstname, lastname FROM names WHERE lastname = "Roe"" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
{
qDebug( "Selected!" );
QSqlRecord rec = qry.record();
int cols = rec.count();
for( int c=0; c<cols; c++ )
qDebug() << QString( "Column %1: %2" ).arg( c ).arg( rec.fieldName(c) );
for( int r=0; qry.next(); r++ )
for( int c=0; c<cols; c++ )
qDebug() << QString( "Row %1, %2: %3" ).arg( r ).arg( rec.fieldName(c) ).arg( qry.value(c).toString() );
}
qry.prepare( "SELECT firstname, lastname FROM names WHERE lastname = "Roe" ORDER BY firstname" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
{
qDebug( "Selected!" );
QSqlRecord rec = qry.record();
int cols = rec.count();
for( int c=0; c<cols; c++ )
qDebug() << QString( "Column %1: %2" ).arg( c ).arg( rec.fieldName(c) );
for( int r=0; qry.next(); r++ )
for( int c=0; c<cols; c++ )
qDebug() << QString( "Row %1, %2: %3" ).arg( r ).arg( rec.fieldName(c) ).arg( qry.value(c).toString() );
}
qry.prepare( "SELECT lastname, COUNT(*) as "members" FROM names GROUP BY lastname ORDER BY lastname" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
{
qDebug( "Selected!" );
QSqlRecord rec = qry.record();
int cols = rec.count();
for( int c=0; c<cols; c++ )
qDebug() << QString( "Column %1: %2" ).arg( c ).arg( rec.fieldName(c) );
for( int r=0; qry.next(); r++ )
for( int c=0; c<cols; c++ )
qDebug() << QString( "Row %1, %2: %3" ).arg( r ).arg( rec.fieldName(c) ).arg( qry.value(c).toString() );
}
qry.prepare( "UPDATE names SET firstname = "Nisse", lastname = "Svensson" WHERE id = 7" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Updated!" );
qry.prepare( "UPDATE names SET lastname = "Johnson" WHERE firstname = "Jane"" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Updated!" );
qry.prepare( "DELETE FROM names WHERE id = 7" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Deleted!" );
qry.prepare( "DELETE FROM names WHERE lastname = "Johnson"" );
if( !qry.exec() )
qDebug() << qry.lastError();
else
qDebug( "Deleted!" );
db.close(); return 0;
}
</source>
