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我想學習一個項目的Wt，現在我正試圖學習它的數據庫部分。Wt數據庫Wt :: Dbo
我被困在一開始。我試圖從dbo教程中學習它（在網站http://www.webtoolkit.eu/wt/doc/tutorial/dbo/tutorial.html#_installing_tt_wt_dbo_tt中有一個教程），它在Wt包（tutorial1.C）中的示例中
我在ubuntu中使用Qt編譯器（5.） 。我已經構建了Wt :: Dbo庫，正如它在網站教程中所述（鏈接在上面）。問題是它仍然給出了一個錯誤，
找不到LGL
collect2：LD返回1退出狀態
下面是來自內重量（從tutorial1.C直接複製）
/*
* Copyright (C) 2010 Emweb bvba, Kessel-Lo, Belgium.
*
* See the LICENSE file for terms of use.
*/
/*****
* This file is part of the Wt::Dbo tutorial:
* http://www.webtoolkit.eu/wt/doc/tutorial/dbo/tutorial.html
*****/
#include <Wt/Dbo/Dbo>
#include <Wt/Dbo/backend/Sqlite3>
#include <string>
namespace dbo = Wt::Dbo;
/*****
* Dbo tutorial section 2. Mapping a single class
*****/
class User {
public:
enum Role {
Visitor = 0,
Admin = 1,
Alien = 42
};
std::string name;
std::string password;
Role role;
int karma;
template<class Action>
void persist(Action& a)
{
dbo::field(a, name, "name");
dbo::field(a, password, "password");
dbo::field(a, role, "role");
dbo::field(a, karma, "karma");
}
};
void run()
{
/*****
* Dbo tutorial section 3. A first session
*****/
/*
* Setup a session, would typically be done once at application startup.
*
* For testing, we'll be using Sqlite3's special :memory: database. You
* can replace this with an actual filename for actual persistence.
*/
dbo::backend::Sqlite3 sqlite3(":memory:");
sqlite3.setProperty("show-queries", "true");
dbo::Session session;
session.setConnection(sqlite3);
session.mapClass<User>("user");
/*
* Try to create the schema (will fail if already exists).
*/
session.createTables();
{
dbo::Transaction transaction(session);
User *user = new User();
user->name = "Joe";
user->password = "Secret";
user->role = User::Visitor;
user->karma = 13;
dbo::ptr<User> userPtr = session.add(user);
}
/*****
* Dbo tutorial section 4. Querying objects
*****/
{
dbo::Transaction transaction(session);
dbo::ptr<User> joe = session.find<User>().where("name = ?").bind("Joe");
std::cerr << "Joe has karma: " << joe->karma << std::endl;
dbo::ptr<User> joe2 = session.query< dbo::ptr<User> >
("select u from user u").where("name = ?").bind("Joe");
}
{
dbo::Transaction transaction(session);
typedef dbo::collection< dbo::ptr<User> > Users;
Users users = session.find<User>();
std::cerr << "We have " << users.size() << " users:" << std::endl;
for (Users::const_iterator i = users.begin(); i != users.end(); ++i)
std::cerr << " user " << (*i)->name
<< " with karma of " << (*i)->karma << std::endl;
}
/*****
* Dbo tutorial section 5. Updating objects
*****/
{
dbo::Transaction transaction(session);
dbo::ptr<User> joe = session.find<User>().where("name = ?").bind("Joe");
joe.modify()->karma++;
joe.modify()->password = "public";
}
{
dbo::Transaction transaction(session);
dbo::ptr<User> joe = session.find<User>().where("name = ?").bind("Joe");
if (joe)
joe.remove();
}
{
dbo::Transaction transaction(session);
dbo::ptr<User> silly = session.add(new User());
silly.modify()->name = "Silly";
silly.remove();
}
}
int main(int argc, char **argv)
{
run();
}
提前感謝代碼