本人用micro2440开发一个系统，最近用Qt做一个带数据库的程序时出现了问题，求大神帮忙。
先是用Qt自带的例子querymodel测试，在PC机上能正常运行，win7系统。如图：
但是经编译移植到开发板上之后却出现了这样的问题：
QTableView上不能显示数据！！
我试过自己编的很多例子都是这样的问题，貌似数据库链接没啥问题吧，但是就是数据不能显示。
不知道是不是我板子上的某些路径设置得不正确，真心求有知道的牛人帮忙解释一下，不甚感激。
附带程序：
//connection.h
#ifndef CONNECTION_H
#define CONNECTION_H
#include <QMessageBox>
#include <QSqlDatabase>
#include <QSqlError>
#include <QSqlQuery>
static bool createConnection()
{
QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
db.setDatabaseName(":memory:");
if (!db.open()) {
QMessageBox::critical(0, qApp->tr("Cannot open database"),
qApp->tr("Unable to establish a database connection.\n"
"This example needs SQLite support. Please read "
"the Qt SQL driver documentation for information how "
"to build it.\n\n"
"Click Cancel to exit."), QMessageBox::Cancel);
return false;
}
QSqlQuery query;
query.exec("create table person (id int primary key, "
"firstname varchar(20), lastname varchar(20))");
query.exec("insert into person values(101, 'Danny', 'Young')");
query.exec("insert into person values(102, 'Christine', 'Holand')");
query.exec("insert into person values(103, 'Lars', 'Gordon')");
query.exec("insert into person values(104, 'Roberto', 'Robitaille')");
query.exec("insert into person values(105, 'Maria', 'Papadopoulos')");
query.exec("create table offices (id int primary key,"
"imagefile int,"
"location varchar(20),"
"country varchar(20),"
"description varchar(100))");
query.exec("insert into offices "
"values(0, 0, 'Oslo', 'Norway',"
"'Oslo is home to more than 500 000 citizens and has a "
"lot to offer.It has been called \"The city with the big "
"heart\" and this is a nickname we are happy to live up to.')");
query.exec("insert into offices "
"values(1, 1, 'Brisbane', 'Australia',"
"'Brisbane is the capital of Queensland, the Sunshine State, "
"where it is beautiful one day, perfect the next. "
"Brisbane is Australia''s 3rd largest city, being home "
"to almost 2 million people.')");
query.exec("insert into offices "
"values(2, 2, 'Redwood City', 'US',"
"'You find Redwood City in the heart of the Bay Area "
"just north of Silicon Valley. The largest nearby city is "
"San Jose which is the third largest city in California "
"and the 10th largest in the US.')");
query.exec("insert into offices "
"values(3, 3, 'Berlin', 'Germany',"
"'Berlin, the capital of Germany is dynamic, cosmopolitan "
"and creative, allowing for every kind of lifestyle. "
"East meets West in the metropolis at the heart of a "
"changing Europe.')");
query.exec("insert into offices "
"values(4, 4, 'Munich', 'Germany',"
"'Several technology companies are represented in Munich, "
"and the city is often called the \"Bavarian Silicon Valley\". "
"The exciting city is also filled with culture, "
"art and music. ')");
query.exec("insert into offices "
"values(5, 5, 'Beijing', 'China',"
"'Beijing as a capital city has more than 3000 years of "
"history. Today the city counts 12 million citizens, and "
"is the political, economic and cultural centre of China.')");
query.exec("create table images (locationid int, file varchar(20))");
query.exec("insert into images values(0, 'images/oslo.png')");
query.exec("insert into images values(1, 'images/brisbane.png')");
query.exec("insert into images values(2, 'images/redwood.png')");
query.exec("insert into images values(3, 'images/berlin.png')");
query.exec("insert into images values(4, 'images/munich.png')");
query.exec("insert into images values(5, 'images/beijing.png')");
return true;
}
#endif
//customsqlmodel.h
#ifndef CUSTOMSQLMODEL_H
#define CUSTOMSQLMODEL_H
#include <QSqlQueryModel>
class CustomSqlModel : public QSqlQueryModel
{
Q_OBJECT
public:
CustomSqlModel(QObject *parent = 0);
QVariant data(const QModelIndex &item, int role) const;
};
#endif
//editablesqlmodel.h
#ifndef EDITABLESQLMODEL_H
#define EDITABLESQLMODEL_H
#include <QSqlQueryModel>
class EditableSqlModel : public QSqlQueryModel
{
Q_OBJECT
public:
EditableSqlModel(QObject *parent = 0);
Qt::ItemFlags flags(const QModelIndex &index) const;
bool setData(const QModelIndex &index, const QVariant &value, int role);
private:
bool setFirstName(int personId, const QString &firstName);
bool setLastName(int personId, const QString &lastName);
void refresh();
};
#endif
//customsqlmodel.cpp
#include <QtGui>
#include "customsqlmodel.h"
CustomSqlModel::CustomSqlModel(QObject *parent)
: QSqlQueryModel(parent)
{
}
QVariant CustomSqlModel::data(const QModelIndex &index, int role) const
{
QVariant value = QSqlQueryModel::data(index, role);
if (value.isValid() && role == Qt::DisplayRole) {
if (index.column() == 0)
return value.toString().prepend("#");
else if (index.column() == 2)
return value.toString().toUpper();
}
if (role == Qt::TextColorRole && index.column() == 1)
return qVariantFromValue(QColor(Qt::blue));
return value;
}
//editablesqlmodel.cpp
#include <QtSql>
#include "editablesqlmodel.h"
EditableSqlModel::EditableSqlModel(QObject *parent)
: QSqlQueryModel(parent)
{
}
Qt::ItemFlags EditableSqlModel::flags(
const QModelIndex &index) const
{
Qt::ItemFlags flags = QSqlQueryModel::flags(index);
if (index.column() == 1 || index.column() == 2)
flags |= Qt::ItemIsEditable;
return flags;
}
bool EditableSqlModel::setData(const QModelIndex &index, const QVariant &value, int /* role */)
{
if (index.column() < 1 || index.column() > 2)
return false;
QModelIndex primaryKeyIndex = QSqlQueryModel::index(index.row(), 0);
int id = data(primaryKeyIndex).toInt();
clear();
bool ok;
if (index.column() == 1) {
ok = setFirstName(id, value.toString());
} else {
ok = setLastName(id, value.toString());
}
refresh();
return ok;
}
void EditableSqlModel::refresh()
{
setQuery("select * from person");
setHeaderData(0, Qt::Horizontal, QObject::tr("ID"));
setHeaderData(1, Qt::Horizontal, QObject::tr("First name"));
setHeaderData(2, Qt::Horizontal, QObject::tr("Last name"));
}
//! [2]
bool EditableSqlModel::setFirstName(int personId, const QString &firstName)
{
QSqlQuery query;
query.prepare("update person set firstname = ? where id = ?");
query.addBindValue(firstName);
query.addBindValue(personId);
return query.exec();
}
//! [2]
bool EditableSqlModel::setLastName(int personId, const QString &lastName)
{
QSqlQuery query;
query.prepare("update person set lastname = ? where id = ?");
query.addBindValue(lastName);
query.addBindValue(personId);
return query.exec();
}
//main.cpp
#include <QtGui>
#include "connection.h"
#include "customsqlmodel.h"
#include "editablesqlmodel.h"
void initializeModel(QSqlQueryModel *model)
{
model->setQuery("select * from person");
model->setHeaderData(0, Qt::Horizontal, QObject::tr("ID"));
model->setHeaderData(1, Qt::Horizontal, QObject::tr("First name"));
model->setHeaderData(2, Qt::Horizontal, QObject::tr("Last name"));
}
void createView(const QString &title, QSqlQueryModel *model)
{
static int offset = 0;
QTableView *view = new QTableView;
view->setModel(model);
view->setWindowTitle(title);
view->move(100 + offset, 100 + offset);
offset += 20;
view->show();
}
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
if (!createConnection())
return 1;
QSqlQueryModel plainModel;
EditableSqlModel editableModel;
CustomSqlModel customModel;
initializeModel(&plainModel);
initializeModel(&editableModel);
initializeModel(&customModel);
createView(QObject::tr("Plain Query Model"), &plainModel);
createView(QObject::tr("Editable Query Model"), &editableModel);
createView(QObject::tr("Custom Query Model"), &customModel);
return app.exec();
}
