执行SQL语句问题!! [复制链接]

98 void DialogClass::Sqlcheck()
99 {
100     QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
101     db.setHostName(LocalSql->text());
102     db.setUserName(UserSql->text());
103     db.setPassword(PassSql->text());
104     db.setDatabaseName("app");
105     bool ok = db.open();
106     if(ok)
107     {
108     Data->show();
109     BackTime->show();
110     QBack->show();
111     Dataname->show();
112     Backtime->show();
113     BackPath->show();
114     BrowseButton->show();
115
116 //    query.exec("show databases;");
117     bool r = query.exec("select * from app.member where 1;");
118     if(r)
119     {
120         while(query.next())
121         {
122             Dataname->addItem(query.value(0).toString());
123         }
124         Dataname->setCurrentIndex(Dataname->currentIndex()+1);
125     }
126     else
127     {
128         QMessageBox::information(0,"Information","SQL Exec Error!");
129     }
130     db.close();
131     }
132     else
133     {
134         QMessageBox::warning(this,tr("Connect Error:"),QString::fromLocal8Bit("Can't Connect SQL!\n"));
135     }
136 };


数据库链接上了..但是一执行SQL语句的时候提示没有打开数据库..QSqlQuery::exec: database not open

你重新建立了链接，但是却没有说明query作用在该链接上。
加这一句：
query=QSqlQuery(db);

能执行SQL语句了.谢谢..