Question

所以我在代码上遗漏了一些内容，但我无法弄清楚这是什么。我试图将一些值从文本字段中删除到数据库中，但我得到了文章名称的错误。

有人可以帮忙吗？我发布了isert代码和按钮代码。提前谢谢。

Database.cpp

bool    Database::insertStudent(Student &s)
{
bool success = false;
QSqlQuery query(db);
query.prepare("INSERT INTO student (name,lastname,semester,studentid) VALUES (:name,:lastname,:semester,:studentid)");
query.bindValue(":name", s.getname());
query.bindValue(":lastname",s.getlastname());
query.bindValue(":semester", s.getsemester());
query.bindValue(":studentid",s.getstudentid());
query.exec();
if(query.exec()) success = true;
else
{
        qDebug() << "Database error:  "
                 << query.lastError();
}
  return success;
}

MainWindow.cpp

void    MainWindow::addSlot()
{

    if(nameEdit->text().isEmpty() || lastnameEdit->text().isEmpty() || semesterEdit->text().isEmpty() ||
            idEdit->text().isEmpty())
    {
        QMessageBox::critical(this,"Error","Empty fields");
        return;
    }
    Student S(nameEdit->text(),lastnameEdit->text(),semesterEdit->text().toInt(),idEdit->text().toInt());
    mydb->insertStudent(S);
    reloadTable();
}

表名是学生，它有4个我使用此代码创建的字段。

Database::Database()
{
    db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("students.db");
    db.open();
    QSqlQuery q(db);
    q.exec(QString("create table if not exists student(")+
                        QString("id integer primary key autoincrement,")+
                        QString("name varchar(1024),lastname varchar(1024),semester integer,")+
                        QString("studentid integer)"));
}

student.cpp

#include "student.h"

Student::Student()
{
    name="";
    lastname="";
    studentid=0;
    semester=0;
}

Student::Student(QString n,QString l,int s,int p)
{
    name=n;
    lastname=l;
    semester=s;
    studentid=p;
}

QString Student::getname()
{
    return name;
}

QString Student::getlastname()
{
    return lastname;
}

int Student::getstudentid()
{
    return studentid;
}

int Student::getsemester()
{
    return semester;
}

QString Student::toString()
{
    return name+","+lastname+","+QString::number(semester)+","+QString::number(studentid);
}

数据库错误C ++上的“参数计数不匹配”

0 个答案: