unicode - QSqlQuery.exec(query) 为 unicode 字符返回错误的字符

Question

我在 MS SQL 服务器中有一个数据库，我的问题是 unicode 字符！我的“getRecordByCondition”方法中的“query.exec(str)”返回“？” char 用于 nvarchar 字段！但它在“loadToGrid”方法中正确工作。这是我的代码：

void DataAccess::connect()
{
    db=QSqlDatabase::addDatabase("QODBC");
    db.setDatabaseName("TestDB");
}

void DataAccess::disConnect()
{
    QString connection;
    connection = db.connectionName();
    db.close();

}
QVariantList DataAccess::getRecordByCondition(QString tableName, QString condition)
{
    connect();
    QVariantList recordData;
    QString str= " select * from " + tableName + " where " + condition ;
    QSqlRecord record;
    QSqlQuery query(db);
    if(db.open())
    {

        // can run
        if(query.exec(str))
        {
            record=query.record();
            int cols=record.count();
            while (query.next())
            {
                for(int i=0;i<cols;i++)
                {
                    qDebug() << query.value(i); // ??????? ????
                    recordData << query.value(i);
                }
            }
            disConnect();
            //return 1;
        }
        else
        {
          qDebug() <<  "problem!" << db.lastError();
            disConnect();
            //return -1;
        }
    }
    else
    {

        qDebug() <<  "db can not open because:" << db.lastError().text();
        //return -2;
    }
   disConnect();
    return recordData;
}



void DataAccess::loadToGrid(QString tableName, QTableView &grid)
{
    connect();
    if(db.open())
    {
        //Load data
        QString qry="select * from " + tableName;
        QSqlRecord record;
        QSqlQuery query(db);
        if(query.exec(qry))
        {
             record=query.record();
             int cols=record.count();
             int rows=0;
             //make model
             QStandardItemModel *myModel=new QStandardItemModel(0,cols,grid.parent());
             //make headers
             for(int i=0;i<cols;i++)
             {
                 myModel->setHorizontalHeaderItem(i,new QStandardItem(record.fieldName(i)));
             }
             while (query.next()) {

                for(int i=0;i<cols;i++)
                {
                    myModel->setItem(rows,i,new QStandardItem(query.value(i).toString()));
                }
                rows++;
             }
             grid.setModel(myModel);

        }
    }
   disConnect();
}

Answer 1

我解决了这个问题，我只改变了我的连接方法

void DataAccess::connect()
{

    if(!db.open())
    {
        db=QSqlDatabase::addDatabase("QODBC");
        db.setDatabaseName("TCOM");
    }
}