Qt+MySQL+MinGW32+更改MySQL数据库的存储位置+数据读取、显示、存储三线程代码

下载

1.在这个安装包下载地址点击右侧【Looking for the latest GA version?】后，下载第二个，并安装。
2.在这个下载地址，下载32位的（两次下载的版本号最好对应）。

配置

下载后解压，将lib文件夹下的libmysql.dll和libmysql.lib复制到qt里

//    qDebug() << loader.load();
    //打印驱动名
    //qDebug() << QSqlDatabase::drivers();
    //添加一个数据库
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    //设置数据库
    db.setHostName("localhost");
    db.setDatabaseName("mysql");//Mysql的名字
    db.setUserName("root");//登录Mysql的用户名
    db.setPassword("root");//登录Mysql的密码
    //打开数据库
    if(db.open() == false)
    {
        QMessageBox::warning(this, "warning", db.lastError().text());
    }
    else
    {
        qDebug() << true;
    }

更改MySQL数据库的存储位置

• 将目录

datadir=C:/ProgramData/MySQL/MySQL Server 5.7/Data

下的文件复制到新的目录

datadir=D:\MySQL\data

• 将目录

 C:\ProgramData\MySQL\MySQL Server 5.7

下的my.ini 文件的

datadir=C:/ProgramData/MySQL/MySQL Server 5.7/Data

更改为自己设定的路径：

datadir=D:\MySQL\data

这里使用了 \

• 重启电脑

出现错误：：

LspTrace]ReadAccConfig returns false!

[LspTrace]FindMatchingProvider: inInfo is one of the LSPs entry.
[LspTrace]WSPStartup end: 0, protocol=17, [not] hook
[LspTrace]FindMatchingProvider: inInfo is one of the LSPs entry.
[LspTrace]WSPStartup end: 0, protocol=6, [not] hook

解决方法：

通过命令提示符修复LSP

1、打开电脑，进入命令提示符窗口，快捷键win+r.

2、在窗口中输入“cmd”进入命令符窗口。

3、在窗口中输入：输入netsh winsock reset，然后按下回车键。

4、然后稍等片刻，出现提示，重启电脑即可。

附上代码：

读取、显示、数据库保存 三线程

widgets.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QDebug>
#include <QSqlDatabase>
#include <QMessageBox>
#include <QSqlError>
#include <QSqlQuery>



//新建串口
void Widget::closeEvent(QCloseEvent* event)
{
    //窗口关闭
    if (threadDaq.isRunning())
    {
        threadDaq.terminate();//结束线程的run()函数执行
        threadDaq.wait();//
    }

    if (threadShow.isRunning())
    {
        threadShow.terminate(); //因为threadB可能处于等待状态，所以用terminate强制结束
        threadShow.wait();//
    }

    if (threadSave.isRunning())
    {
        threadSave.terminate(); //因为threadB可能处于等待状态，所以用terminate强制结束
        threadSave.wait();//
    }

    event->accept();
}


Widget::Widget(QWidget* parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    // qDebug() << loader.load();
    //打印驱动名
    //qDebug() << QSqlDatabase::drivers();
    //添加一个数据库
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    //设置数据库
    db.setHostName("localhost"); //主机IP
    db.setDatabaseName("mydata");//Mysql的名字
    db.setUserName("root");//登录Mysql的用户名
    db.setPassword("root");//登录Mysql的密码
    //打开数据库
    if(db.open() == false)
    {
        QMessageBox::warning(this, "warning", db.lastError().text());
    }

    connect(&threadDaq, SIGNAL(started()), this, SLOT(onthreadDaq_started()));
    connect(&threadDaq, SIGNAL(finished()), this, SLOT(onthreadDaq_finished()));

    connect(&threadShow, SIGNAL(started()), this, SLOT(onthreadShow_started()));
    connect(&threadShow, SIGNAL(finished()), this, SLOT(onthreadShow_finished()));

    connect(&threadSave, SIGNAL(started()), this, SLOT(onthreadSave_started()));
    connect(&threadSave, SIGNAL(finished()), this, SLOT(onthreadSave_finished()));

    connect(&threadShow, SIGNAL(newValue(int, int )), this, SLOT(onthreadB_newValue(int, int  )));
    connect(&threadSave, SIGNAL(saveValue(int, int )), this, SLOT(onthreadB_saveValue(int, int )));

}

Widget::~Widget()
{
    delete ui;
}


/*********************************槽函数*********************************/

void Widget::onthreadDaq_started()
{
    ui->LabA->setText("ThreadDaq状态: started");
}

void Widget::onthreadDaq_finished()
{
    ui->LabA->setText("ThreadDaq状态: finished");
}

void Widget::onthreadShow_started()
{
    ui->LabB->setText("ThreadShow状态: started");
}

void Widget::onthreadShow_finished()
{
    ui->LabB->setText("ThreadShow状态: finished");
}

void Widget::onthreadSave_started()
{
    ui->LabC->setText("ThreadSave状态: started");
}

void Widget::onthreadSave_finished()
{
    ui->LabC->setText("ThreadSave状态: finished");
}

void Widget::on_pushButton_clear_clicked()
{
    ui->plainTextEdit->clear();
}

void Widget::onthreadB_newValue(int seq, int diceValue)
{
    QString  str = QString::asprintf("第 %d 次，数字为：%d", seq, diceValue);
    ui->plainTextEdit->appendPlainText(str);
}

void Widget::onthreadB_saveValue(int seq, int diceValue)
{
    //增删查改
    //添加一条记录
    QSqlQuery query;
    QString s = QString::number(seq, 10);
    QString val = QString::number(diceValue, 10);
    QString sql = "insert into people (nums ,age)  values('" + s + "'," + val + ")";
    query .exec(sql);
}

/******************************控件按钮*********************************/
void Widget::on_pushButton_close_clicked()
{
    //结束线程
//    threadConsumer.stopThread();//结束线程的run()函数执行

    threadDaq.terminate(); //因为threadB可能处于等待状态，所以用terminate强制结束
    threadDaq.wait();//

    threadSave.terminate();//结束线程的run()函数执行
    threadSave.wait();//

    threadShow.terminate();//结束线程的run()函数执行
    threadShow.wait();//

    ui->pushButton_start->setEnabled(true);
    ui->pushButton_close->setEnabled(false);
}

void Widget::on_pushButton_start_clicked()
{

    threadShow.start();
    threadSave.start();
    threadDaq.start();
    ui->pushButton_start->setEnabled(false);
    ui->pushButton_close->setEnabled(true);
}

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTimer>
#include "threads.h"

QT_BEGIN_NAMESPACE
namespace Ui
{
    class Widget;
}
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

private:
    threadDAQ   threadDaq;
    threadShow  threadShow;
    threadSave  threadSave;

protected:
    void    closeEvent(QCloseEvent* event);

public:

    Widget(QWidget* parent = nullptr);
    ~Widget();
private slots:

    void onthreadDaq_started();
    void onthreadDaq_finished();

    void onthreadShow_started();
    void onthreadShow_finished();

    void onthreadSave_started();
    void onthreadSave_finished();
    
    void on_pushButton_clear_clicked();
    
    void onthreadB_newValue(int seq, int val);
    void onthreadB_saveValue(int seq, int val);
    
    void on_pushButton_start_clicked();
    void on_pushButton_close_clicked();
private:
    Ui::Widget* ui;
};
#endif // WIDGET_H

threads.cpp

#include    "threads.h"
#include    <QWaitCondition>
#include    <QTime>
#include    <QMutex>

QMutex  mutex;
QWaitCondition  newdataAvailable;

int     seq = 0; //序号
int     diceValue;

/*********************************获取数据*******************************/


void threadDAQ::stopThread()
{
    QMutexLocker  locker(&mutex);
    m_stop = true;
}

void threadDAQ::run()
{
    m_stop = false; //启动线程时令m_stop=false
    seq = 0;
    qsrand(QTime::currentTime().msec());//随机数初始化，qsrand是线程安全的

    while(!m_stop)//循环主体
    {
        mutex.lock();
        diceValue = qrand(); //获取随机数
        diceValue = (diceValue % 6) + 1;
        seq++;
        mutex.unlock();
        newdataAvailable.wakeAll();//唤醒所有线程，有新数据了
        msleep(500); //线程休眠
    }
}

/*********************************显示数据*******************************/
threadShow::threadShow()
{

}

void threadShow::stopThread()
{
    QMutexLocker  locker(&mutex);
    m_stop = true;
}

void threadShow::run()
{
    m_stop = false; //启动线程时令m_stop=false
    while(!m_stop)//循环主体
    {
        mutex.lock();
        newdataAvailable.wait(&mutex);//会先解锁mutex，使其他线程可以使用mutex
        emit    newValue(seq, diceValue);
        mutex.unlock();
//        msleep(100); //线程休眠100ms
    }
}

/*********************************保存数据*******************************/

threadSave::threadSave()
{

}

void threadSave::stopThread()
{
    QMutexLocker  locker(&mutex);
    m_stop = true;
}

void threadSave::run()
{
    m_stop = false; //启动线程时令m_stop=false
    while(!m_stop)//循环主体
    {
        mutex.lock();
        newdataAvailable.wait(&mutex);//会先解锁mutex，使其他线程可以使用mutex
        emit    saveValue(seq, diceValue);
        mutex.unlock();
//        msleep(100); //线程休眠100ms
    }

}

threads.h

#ifndef THREADS_H
#define THREADS_H
//#include  <QObject>
#include  <QThread>
#include  <QSerialPort>
#include  <QTimer>
#include  <QDebug>
#include  <QSerialPortInfo>

/*********************************获取数据*******************************/
class threadDAQ : public QThread
{
    Q_OBJECT

private:
    bool    m_stop = false; //停止线程

protected:
    void    run() Q_DECL_OVERRIDE;

public:
    threadDAQ(QObject* parent = 0) : QThread(parent)
    {

    }
    QSerialPort* m_serial;
    void ThreadopenMycom();
    void  stopThread();

signals:
    void ThreadMyCom(const QString&);
};

/*********************************显示数据*******************************/
class threadShow : public QThread
{
    Q_OBJECT
private:
    bool    m_stop = false; //停止线程
protected:
    void    run() Q_DECL_OVERRIDE;
public:
    threadShow();
    void    stopThread();
signals:
    void  newValue(int seq, int divceValue);

};

/*********************************存储数据*******************************/
class threadSave : public QThread
{
    Q_OBJECT

private:
    bool    m_stop = false; //停止线程
protected:
    void    run() Q_DECL_OVERRIDE;
public:
    threadSave();
    void    stopThread();
signals:
    void  saveValue(int seq,  int diceValue);
};

#endif // THREADS_H

自己记录一下。。。。。。。。。。。。。

本文地址：https://blog.csdn.net/weixin_39308232/article/details/108563849