qsql_psql.cpp

qt专门用于嵌入式的图形开发GUI

			i += 4;
		    } else {
			ba[ index++ ] = val.at( i + 1 );
			i += 2;
		    }
		} else {
		    ba[ index++ ] = val.at( i++ ).unicode();
		}
	    }
	    ba.resize( index );
	    return QVariant( ba );
	}

	QByteArray ba;
	((QSqlDriver*)driver())->beginTransaction();
	Oid oid = val.toInt();
	int fd = lo_open( d->connection, oid, INV_READ );
#ifdef QT_CHECK_RANGE
	if ( fd < 0) {
	    qWarning( "QPSQLResult::data: unable to open large object for read" );
	    ((QSqlDriver*)driver())->commitTransaction();
	    return QVariant( ba );
	}
#endif
	int size = 0;
	int retval = lo_lseek( d->connection, fd, 0L, SEEK_END );
	if ( retval >= 0 ) {
	    size = lo_tell( d->connection, fd );
	    lo_lseek( d->connection, fd, 0L, SEEK_SET );
	}
	if ( size == 0 ) {
	    lo_close( d->connection, fd );
	    ((QSqlDriver*)driver())->commitTransaction();
	    return QVariant( ba );
	}
	char * buf = new char[ size ];

#ifdef Q_OS_WIN32
	// ### For some reason lo_read() fails if we try to read more than
	// ### 32760 bytes
	char * p = buf;
	int nread = 0;

	while( size < nread ){
		retval = lo_read( d->connection, fd, p, 32760 );
		nread += retval;
		p += retval;
	}
#else
	retval = lo_read( d->connection, fd, buf, size );
#endif

	if (retval < 0) {
	    qWarning( "QPSQLResult::data: unable to read large object" );
	} else {
	    ba.duplicate( buf, size );
	}
	delete [] buf;
	lo_close( d->connection, fd );
	((QSqlDriver*)driver())->commitTransaction();
	return QVariant( ba );
    }
    default:
    case QVariant::Invalid:
#ifdef QT_CHECK_RANGE
	qWarning("QPSQLResult::data: unknown data type");
#endif
	;
    }
    return QVariant();
}

bool QPSQLResult::isNull( int field )
{
    PQgetvalue( d->result, at(), field );
    return PQgetisnull( d->result, at(), field );
}

bool QPSQLResult::reset ( const QString& query )
{
    cleanup();
    if ( !driver() )
	return FALSE;
    if ( !driver()->isOpen() || driver()->isOpenError() )
	return FALSE;
    setActive( FALSE );
    setAt( QSql::BeforeFirst );
    if ( d->result )
	PQclear( d->result );
    if ( d->isUtf8 ) {
	d->result = PQexec( d->connection, query.utf8().data() );
    } else {
	d->result = PQexec( d->connection, query.local8Bit().data() );
    }
    int status =  PQresultStatus( d->result );
    if ( status == PGRES_COMMAND_OK || status == PGRES_TUPLES_OK ) {
	if ( status == PGRES_TUPLES_OK ) {
	    setSelect( TRUE );
	    currentSize = PQntuples( d->result );
	} else {
	    setSelect( FALSE );
	    currentSize = -1;
	}
	setActive( TRUE );
	return TRUE;
    }
    setLastError( qMakeError( "Unable to create query", QSqlError::Statement, d ) );
    return FALSE;
}

int QPSQLResult::size()
{
    return currentSize;
}

int QPSQLResult::numRowsAffected()
{
    return QString( PQcmdTuples( d->result ) ).toInt();
}

///////////////////////////////////////////////////////////////////

static bool setEncodingUtf8( PGconn* connection )
{
    PGresult* result = PQexec( connection, "SET CLIENT_ENCODING TO 'UNICODE'" );
    int status = PQresultStatus( result );
    PQclear( result );
    return status == PGRES_COMMAND_OK;
}

static void setDatestyle( PGconn* connection )
{
    PGresult* result = PQexec( connection, "SET DATESTYLE TO 'ISO'" );
#ifdef QT_CHECK_RANGE
    int status =  PQresultStatus( result );
    if ( status != PGRES_COMMAND_OK )
        qWarning( "%s", PQerrorMessage( connection ) );
#endif
    PQclear( result );
}

static QPSQLDriver::Protocol getPSQLVersion( PGconn* connection )
{
    PGresult* result = PQexec( connection, "select version()" );
    int status =  PQresultStatus( result );
    if ( status == PGRES_COMMAND_OK || status == PGRES_TUPLES_OK ) {
	QString val( PQgetvalue( result, 0, 0 ) );
	PQclear( result );
	QRegExp rx( "(\\d+)\\.(\\d+)" );
	rx.setMinimal ( TRUE ); // enforce non-greedy RegExp
        if ( rx.search( val ) != -1 ) {
	    int vMaj = rx.cap( 1 ).toInt();
	    int vMin = rx.cap( 2 ).toInt();
	    if ( vMaj < 6 ) {
#ifdef QT_CHECK_RANGE
		qWarning( "This version of PostgreSQL is not supported and may not work." );
#endif
		return QPSQLDriver::Version6;
	    }
	    if ( vMaj == 6 ) {
		return QPSQLDriver::Version6;
	    } else if ( vMaj == 7 ) {
		if ( vMin < 1 )
		    return QPSQLDriver::Version7;
		else if ( vMin < 3 )
		    return QPSQLDriver::Version71;
	    }
	    return QPSQLDriver::Version73;
	}
    } else {
#ifdef QT_CHECK_RANGE
	qWarning( "This version of PostgreSQL is not supported and may not work." );
#endif
    }

    return QPSQLDriver::Version6;
}

QPSQLDriver::QPSQLDriver( QObject * parent, const char * name )
    : QSqlDriver(parent,name ? name : "QPSQL"), pro( QPSQLDriver::Version6 )
{
    init();
}

QPSQLDriver::QPSQLDriver( PGconn * conn, QObject * parent, const char * name )
    : QSqlDriver(parent,name ? name : "QPSQL"), pro( QPSQLDriver::Version6 )
{
    init();
    d->connection = conn;
    if ( conn ) {
	pro = getPSQLVersion( d->connection );
	setOpen( TRUE );
	setOpenError( FALSE );
    }
}

void QPSQLDriver::init()
{
    qSqlDriverExtDict()->insert( this, new QPSQLDriverExtension(this) );
    qSqlOpenExtDict()->insert( this, new QPSQLOpenExtension(this) );

    d = new QPSQLPrivate();
}

QPSQLDriver::~QPSQLDriver()
{
    if ( d->connection )
	PQfinish( d->connection );
    delete d;
    if ( !qSqlDriverExtDict()->isEmpty() ) {
	QSqlDriverExtension *ext = qSqlDriverExtDict()->take( this );
	delete ext;
    }
    if ( !qSqlOpenExtDict()->isEmpty() ) {
	QSqlOpenExtension *ext = qSqlOpenExtDict()->take( this );
	delete ext;
    }
}

PGconn* QPSQLDriver::connection()
{
    return d->connection;
}


bool QPSQLDriver::hasFeature( DriverFeature f ) const
{
    switch ( f ) {
    case Transactions:
	return TRUE;
    case QuerySize:
	return TRUE;
    case BLOB:
	return pro >= QPSQLDriver::Version71;
    case Unicode:
	return d->isUtf8;
    default:
	return FALSE;
    }
}

bool QPSQLDriver::open( const QString&,
			const QString&,
			const QString&,
			const QString&,
			int )
{
    qWarning("QPSQLDriver::open(): This version of open() is no longer supported." );
    return FALSE;
}

bool QPSQLDriver::open( const QString & db,
			const QString & user,
			const QString & password,
			const QString & host,
			int port,
			const QString& connOpts )
{
    if ( isOpen() )
	close();
    QString connectString;
    if ( host.length() )
	connectString.append( "host=" ).append( host );
    if ( db.length() )
	connectString.append( " dbname=" ).append( db );
    if ( user.length() )
	connectString.append( " user=" ).append( user );
    if ( password.length() )
	connectString.append( " password=" ).append( password );
    if ( port > -1 )
	connectString.append( " port=" ).append( QString::number( port ) );

    // add any connect options - the server will handle error detection
    if ( !connOpts.isEmpty() )
	connectString += " " + QStringList::split( ';', connOpts ).join( " " );

    d->connection = PQconnectdb( connectString.local8Bit().data() );
    if ( PQstatus( d->connection ) == CONNECTION_BAD ) {
	setLastError( qMakeError("Unable to connect", QSqlError::Connection, d ) );
	setOpenError( TRUE );
	return FALSE;
    }

    pro = getPSQLVersion( d->connection );
    d->isUtf8 = setEncodingUtf8( d->connection );
    setDatestyle( d->connection );

    setOpen( TRUE );
    setOpenError( FALSE );
    return TRUE;
}

void QPSQLDriver::close()
{
    if ( isOpen() ) {
        if (d->connection)
	    PQfinish( d->connection );
	d->connection = 0;
	setOpen( FALSE );
	setOpenError( FALSE );
    }
}

QSqlQuery QPSQLDriver::createQuery() const
{
    return QSqlQuery( new QPSQLResult( this, d ) );
}

bool QPSQLDriver::beginTransaction()
{
    if ( !isOpen() ) {
#ifdef QT_CHECK_RANGE
	qWarning( "QPSQLDriver::beginTransaction: Database not open" );
#endif
	return FALSE;
    }
    PGresult* res = PQexec( d->connection, "BEGIN" );
    if ( !res || PQresultStatus( res ) != PGRES_COMMAND_OK ) {
	PQclear( res );
	setLastError( qMakeError( "Could not begin transaction", QSqlError::Transaction, d ) );
	return FALSE;
    }
    PQclear( res );
    return TRUE;
}

bool QPSQLDriver::commitTransaction()
{
    if ( !isOpen() ) {
#ifdef QT_CHECK_RANGE
	qWarning( "QPSQLDriver::commitTransaction: Database not open" );
#endif
	return FALSE;
    }
    PGresult* res = PQexec( d->connection, "COMMIT" );
    if ( !res || PQresultStatus( res ) != PGRES_COMMAND_OK ) {
	PQclear( res );
	setLastError( qMakeError( "Could not commit transaction", QSqlError::Transaction, d ) );
	return FALSE;
    }
    PQclear( res );
    return TRUE;
}

bool QPSQLDriver::rollbackTransaction()
{
    if ( !isOpen() ) {
#ifdef QT_CHECK_RANGE
	qWarning( "QPSQLDriver::rollbackTransaction: Database not open" );
#endif
	return FALSE;
    }
    PGresult* res = PQexec( d->connection, "ROLLBACK" );
    if ( !res || PQresultStatus( res ) != PGRES_COMMAND_OK ) {
	setLastError( qMakeError( "Could not rollback transaction", QSqlError::Transaction, d ) );
	PQclear( res );
	return FALSE;
    }
    PQclear( res );
    return TRUE;
}

QStringList QPSQLDriver::tables( const QString& typeName ) const
{
    QStringList tl;
    if ( !isOpen() )
	return tl;
    int type = typeName.toInt();
    QSqlQuery t = createQuery();
    t.setForwardOnly( TRUE );