Qt5.9數據庫操作sqlite完整例子

先上效果圖吧:

 

 本例子連接：

鏈接：https://pan.baidu.com/s/17JmeJGvoj7oJROcNsBX6Kg   提取碼：b051

    有關數據庫的操作部分，可以學習下sqlite編程，如果你還不會數據庫編程的話，那要加油去看看基本的東西了。本例子是基於
sqlite3 的編程，下面我們一起來看看吧。

首先是工程文件中一定要加：

QT       += sql

主界面的頭文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include    <QLabel>
#include    <QString>

#include <QtSql>
#include <QDataWidgetMapper>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

private:
    QSqlDatabase DB; //數據庫
    QSqlQueryModel *qryModel; //數據庫模型
    QItemSelectionModel *theSelection; //選擇模型
private:
    void  openTable();//打開數據表
    void  updateRecord(int recNo); //更新記錄
public:
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void on_actOpenDB_triggered();

    void on_actRecInsert_triggered();

    void on_actRecDelete_triggered();

    void on_actRecEdit_triggered();

    void on_actScan_triggered();

    void on_tableView_doubleClicked(const QModelIndex &index);

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

主頁面佈局： 

 

設置界面的佈局：

這個類是WDialogData 繼承爲 QDialog

來看：

#ifndef WDIALOGDATA_H
#define WDIALOGDATA_H

#include <QDialog>
#include    <QSqlRecord>

namespace Ui {
class WDialogData;
}

class WDialogData : public QDialog
{
    Q_OBJECT
private:
     QSqlRecord  mRecord; //保存一條記錄的數據

public:
    explicit WDialogData(QWidget *parent = nullptr);
    ~WDialogData();

     void    setUpdateRecord(QSqlRecord &recData); //更新記錄
     void    setInsertRecord(QSqlRecord &recData); //插入記錄

     QSqlRecord  getRecordData();//獲取錄入的數據

private slots:
     void on_btnSetPhoto_clicked();

     void on_btnClearPhoto_clicked();

private:
    Ui::WDialogData *ui;
};

#endif // WDIALOGDATA_H

這裏確定與取消要設定爲:

這樣目的可以與主頁面進行頁面的交互。

對應的cpp文件：

#include "wdialogdata.h"
#include "ui_wdialogdata.h"
#include    <QFileDialog>

WDialogData::WDialogData(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::WDialogData)
{
    ui->setupUi(this);
}

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

void WDialogData::setUpdateRecord(QSqlRecord &recData)
{
  //編輯記錄，更新記錄數據到界面
    mRecord = recData;
    ui->spinEmpNo->setEnabled(false); //員工編號不許編程
    setWindowTitle("跟新記錄");
    //根據recData的數據更新界面顯示

    ui->spinEmpNo->setValue(recData.value("empNo").toInt());
    ui->editName->setText(recData.value("Name").toString());
    ui->comboSex->setCurrentText(recData.value("Gender").toString());
    ui->spinHeight->setValue(recData.value("Height").toFloat());
    ui->editBirth->setDate(recData.value("Birthday").toDate());
    ui->editMobile->setText(recData.value("Mobile").toString());
    ui->comboProvince->setCurrentText(recData.value("Province").toString());
    ui->editCity->setText(recData.value("City").toString());
    ui->comboDep->setCurrentText(recData.value("Department").toString());
    ui->comboEdu->setCurrentText(recData.value("Education").toString());
    ui->spinSalary->setValue(recData.value("Salary").toInt());
    ui->editMemo->setPlainText(recData.value("Memo").toString());

    QVariant va=recData.value("Photo");//
    if (!va.isValid())  //圖片字段內容爲空
        ui->LabPhoto->clear();
    else {
        QByteArray data=va.toByteArray();
        QPixmap pic;
        pic.loadFromData(data);
        ui->LabPhoto->setPixmap(pic.scaledToWidth(ui->LabPhoto->size().width()));
    }

}

void WDialogData::setInsertRecord(QSqlRecord &recData)
{
    //插入記錄，無需更新界面顯示，但是要存儲recData的字段結構
    mRecord=recData; //保存recData到內部變量
    ui->spinEmpNo->setEnabled(true); //插入的記錄，員工編號允許編輯
    setWindowTitle("插入新記錄");
    ui->spinEmpNo->setValue(recData.value("empNo").toInt());
}

QSqlRecord WDialogData::getRecordData()
{
    //"確定"按鈕後，界面數據保存到記錄mRecord
        mRecord.setValue("empNo",ui->spinEmpNo->value());
        mRecord.setValue("Name",ui->editName->text());
        mRecord.setValue("Gender",ui->comboSex->currentText());
        mRecord.setValue("Height",ui->spinHeight->value());
        mRecord.setValue("Birthday",ui->editBirth->date());
        mRecord.setValue("Mobile",ui->editMobile->text());

        mRecord.setValue("Province",ui->comboProvince->currentText());
        mRecord.setValue("City",ui->editCity->text());
        mRecord.setValue("Department",ui->comboDep->currentText());

        mRecord.setValue("Education",ui->comboEdu->currentText());
        mRecord.setValue("Salary",ui->spinSalary->value());
        mRecord.setValue("Memo",ui->editMemo->toPlainText());
    //照片編輯時已經修改了mRecord的photo字段的值

     return  mRecord; //以記錄作爲返回值
}

void WDialogData::on_btnSetPhoto_clicked()
{
    QString aFile = QFileDialog::getOpenFileName(this,"選擇圖片文件","",
                                                 "照片(*.jpg)");
    if(aFile.isEmpty())
        return;

    QByteArray data;
    QFile * file  = new QFile(aFile);
    file->open(QIODevice::ReadOnly); //只讀
    data = file->readAll();
    file->close();

    mRecord.setValue("photo",data); //圖片保存到Photo字段
    QPixmap pic;
    pic.loadFromData(data);
    ui->LabPhoto->setPixmap(pic.scaledToWidth(ui->LabPhoto->size().width()));
}

void WDialogData::on_btnClearPhoto_clicked()
{
   //清除照片
    ui->LabPhoto->clear();
    mRecord.setNull("Photo"); //Photo字段清空
}

下面是主頁面中的程序部分：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include    <QFileDialog>
#include    <QMessageBox>
#include "wdialogdata.h"
void MainWindow::openTable()
{
    //打開數據表
    qryModel = new QSqlQueryModel(this);
    theSelection = new QItemSelectionModel(qryModel);

    qryModel->setQuery("SELECT empNo,name,Gender,Height,Birthday,Mobile,"
         "Province, City,Department,Education,Salary FROM employee order by empNo");
    //數據查詢
    if(qryModel->lastError().isValid())
    {
        QMessageBox::information(this, "錯誤", "數據表查詢錯誤,錯誤信息\n"+qryModel->lastError().text(),
                                 QMessageBox::Ok,QMessageBox::NoButton);
        return;
    }

    qryModel->setHeaderData(0,Qt::Horizontal,"工號");
    qryModel->setHeaderData(1,Qt::Horizontal,"姓名");
    qryModel->setHeaderData(2,Qt::Horizontal,"性別");
    qryModel->setHeaderData(3,Qt::Horizontal,"身高");
    qryModel->setHeaderData(4,Qt::Horizontal,"出生日期");
    qryModel->setHeaderData(5,Qt::Horizontal,"手機");
    qryModel->setHeaderData(6,Qt::Horizontal,"省份");
    qryModel->setHeaderData(7,Qt::Horizontal,"城市");
    qryModel->setHeaderData(8,Qt::Horizontal,"部門");
    qryModel->setHeaderData(9,Qt::Horizontal,"學歷");
    qryModel->setHeaderData(10,Qt::Horizontal,"工資");

    ui->tableView->setModel(qryModel);
    ui->tableView->setSelectionModel(theSelection);

    ui->actOpenDB->setEnabled(false);

    ui->actRecInsert->setEnabled(true);
    ui->actRecDelete->setEnabled(true);
    ui->actRecEdit->setEnabled(true);
    ui->actScan->setEnabled(true);

}

void MainWindow::updateRecord(int recNo)
{
    //更新一條記錄
    QSqlRecord curRec=qryModel->record(recNo); //獲取當前記錄
    int empNo = curRec.value("EmpNo").toInt(); //獲取EmpNo
    QSqlQuery query; //查詢出當前記錄的所有字段
    query.prepare("select * from employee where EmpNo = :ID"); //設置準備執行的 SQL 語句，一般用於帶參數的 SQL 語句
    query.bindValue(":ID",empNo); //設置 SQL 語句中參數的俏，以佔位符表示參數
    query.exec();//執行由 prepare（）和 bindValue（）設置的 SQL 語句
    query.first();

    if(!query.isValid()) //判斷是否無效
    {
        return;  //無效返回函數
    }

    curRec = query.record();//返回當前記錄
    //另一個界面
    WDialogData * dataDialog = new WDialogData(this);
    Qt::WindowFlags    flags=dataDialog->windowFlags();
    dataDialog->setWindowFlags(flags | Qt::MSWindowsFixedSizeDialogHint); //設置對話框固定大小

    dataDialog->setUpdateRecord(curRec);//調用對話框函數更新數據和界面
     int ret=dataDialog->exec();// 以模態方式顯示對話框
     if(ret == QDialog::Accepted) //OK鍵被按下
     {
         QSqlRecord recData = dataDialog->getRecordData();//獲取返回的數據
         query.prepare("update employee set Name = :Name, Gender = :Gender,Height=:Height,"
                       " Birthday=:Birthday, Mobile=:Mobile, Province=:Province,"
                       " City=:City, Department=:Department, Education=:Education,"
                       " Salary=:Salary, Memo=:Memo, Photo=:Photo "
                       " where EmpNo = :ID");
         query.bindValue(":Name",recData.value("Name"));
         query.bindValue(":Gender",recData.value("Gender"));
         query.bindValue(":Height",recData.value("Height"));
         query.bindValue(":Birthday",recData.value("Birthday"));
         query.bindValue(":Mobile",recData.value("Mobile"));

         query.bindValue(":Province",recData.value("Province"));
         query.bindValue(":City",recData.value("City"));
         query.bindValue(":Department",recData.value("Department"));
         query.bindValue(":Education",recData.value("Education"));

         query.bindValue(":Salary",recData.value("Salary"));
         query.bindValue(":Memo",recData.value("Memo"));
         query.bindValue(":Photo",recData.value("Photo"));

         query.bindValue(":ID",empNo);

         if(!query.exec())
         {
             QMessageBox::critical(this, "錯誤", "記錄更新錯誤\n"+query.lastError().text(),
                                      QMessageBox::Ok,QMessageBox::NoButton);
         }
         else {
            qryModel->query().exec();//數據模型重新查詢數據，更新tableView顯示
//             qryModel->setQuery("SELECT empNo,name,Gender,Height,Birthday,Mobile,"
//                  "Province, City,Department,Education,Salary FROM employee order by empNo");
           qryModel->layoutChanged();

         }
     }
}

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    this->setCentralWidget(ui->tableView); //設置爲中間

    ui->tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    ui->tableView->setSelectionMode(QAbstractItemView::SingleSelection);
    ui->tableView->setAlternatingRowColors(true);

}

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

void MainWindow::on_actOpenDB_triggered()
{
     QString aFile = QFileDialog::getOpenFileName(this,"選擇數據庫文件","",
                                                  "SQL Lite數據庫(*.db *.db3)");
     if(aFile.isEmpty())
     {
         QMessageBox::warning(this, "錯誤", "打開數據庫失敗",
                                  QMessageBox::Ok,QMessageBox::NoButton);
         return;
     }
   //打開數據庫
     DB = QSqlDatabase::addDatabase("QSQLITE");  //添加 SQL LITE數據庫驅動
     DB.setDatabaseName(aFile);

     if(!DB.open())
     {
         QMessageBox::warning(this, "錯誤", "打開數據庫失敗",
                                  QMessageBox::Ok,QMessageBox::NoButton);
         return;
     }
    //打開數據表
    openTable();
}

void MainWindow::on_actRecInsert_triggered()
{
    //插入記錄
    QSqlQuery query;
    query.exec("select * from employee where EmpNo =-1"); //實際不查詢出記錄，只查詢字段信息
    QSqlRecord curRec = query.record(); //獲取當前記錄,實際爲空記錄
    curRec.setValue("EmpNo",qryModel->rowCount()+3000);

    WDialogData    *dataDialog=new WDialogData(this);
    Qt::WindowFlags    flags=dataDialog->windowFlags();
    dataDialog->setWindowFlags(flags | Qt::MSWindowsFixedSizeDialogHint); //設置對話框固定大小

    dataDialog->setInsertRecord(curRec);
    int ret=dataDialog->exec();// 以模態方式顯示對話框
    if(ret == QDialog::Accepted) //OK鍵按下去後
    {
        QSqlRecord recData = dataDialog->getRecordData();

        query.prepare("INSERT INTO employee (EmpNo,Name,Gender,Height,Birthday,Mobile,Province,"
                      " City,Department,Education,Salary,Memo,Photo) "
                      " VALUES(:EmpNo,:Name, :Gender,:Height,:Birthday,:Mobile,:Province,"
                      " :City,:Department,:Education,:Salary,:Memo,:Photo)");
        query.bindValue(":EmpNo",recData.value("EmpNo"));
        query.bindValue(":Name",recData.value("Name"));
        query.bindValue(":Gender",recData.value("Gender"));
        query.bindValue(":Height",recData.value("Height"));
        query.bindValue(":Birthday",recData.value("Birthday"));
        query.bindValue(":Mobile",recData.value("Mobile"));

        query.bindValue(":Province",recData.value("Province"));
        query.bindValue(":City",recData.value("City"));
        query.bindValue(":Department",recData.value("Department"));
        query.bindValue(":Education",recData.value("Education"));

        query.bindValue(":Salary",recData.value("Salary"));
        query.bindValue(":Memo",recData.value("Memo"));
        query.bindValue(":Photo",recData.value("Photo"));

        if(!query.exec())
        {
            QMessageBox::critical(this, "錯誤", "插入記錄錯誤\n"+query.lastError().text(),
                                     QMessageBox::Ok,QMessageBox::NoButton);
        }
        else {
//            qryModel->query().exec();//數據模型重新查詢數據，更新tableView顯示
            qryModel->setQuery("SELECT empNo,name,Gender,Height,Birthday,Mobile,"
                 "Province, City,Department,Education,Salary FROM employee order by empNo");
        }
    }

    delete dataDialog;
}

void MainWindow::on_actRecDelete_triggered()
{
    //刪除當前記錄
    int curRecNo = theSelection->currentIndex().row();
    QSqlRecord curRec = qryModel->record(curRecNo);
    if (curRec.isEmpty()) //當前爲空記錄
        return;

    int empNo=curRec.value("EmpNo").toInt();//獲取員工編號
    QSqlQuery query;
    query.prepare("delete  from employee where EmpNo = :ID");
    query.bindValue(":ID",empNo);
    if (!query.exec())
        QMessageBox::critical(this, "錯誤", "刪除記錄出現錯誤\n"+query.lastError().text(),
                                 QMessageBox::Ok,QMessageBox::NoButton);
    else //插入，刪除記錄後需要重新設置SQL語句查詢
    {
       qryModel->query().exec();
//        qryModel->setQuery("SELECT empNo,name,Gender,Height,Birthday,Mobile,"
//             "Province, City,Department,Education,Salary FROM employee order by empNo");
       qryModel->layoutChanged();
    }

//    ui->tableView->update();
}

void MainWindow::on_actRecEdit_triggered()
{
    int curRecNo=theSelection->currentIndex().row();
    updateRecord(curRecNo);
}

void MainWindow::on_actScan_triggered()
{
   //漲工資，記錄遍歷
   QSqlQuery qryEmpList; //員工工資信息列表
   qryEmpList.exec("SELECT empNo,Salary FROM employee ORDER BY empNo");
   qryEmpList.first();

   QSqlQuery qryUpdate; //臨時 QSqlQuery
   qryUpdate.prepare("UPDATE employee SET Salary=:Salary WHERE EmpNo = :ID");

   while(qryEmpList.isValid()) //當前記錄有效
   {
       int empID=qryEmpList.value("empNo").toInt(); //獲取empNo
       float salary=qryEmpList.value("Salary").toFloat(); //獲取Salary
       salary=salary+1000; //漲工資

       qryUpdate.bindValue(":ID",empID);
       qryUpdate.bindValue(":Salary",salary); //設置SQL語句參數
       qryUpdate.exec(); //執行UPDATE

       if (!qryEmpList.next()) //移動到下一條記錄，並判斷是否到末尾了
           break;
   }

    qryModel->query().exec();//數據模型重新查詢數據，更新tableView的顯示
    QMessageBox::information(this, "提示", "漲工資計算完畢",
                             QMessageBox::Ok,QMessageBox::NoButton);
}


void MainWindow::on_tableView_doubleClicked(const QModelIndex &index)
{
    //雙擊編輯
    int curRecNo=index.row();
    updateRecord(curRecNo);
}

         這裏大部分代碼都是qt5.9開發實例書上的代碼，其中的知識點可以看這本書，需要資源也可以私信我，這裏只是簡單記錄這個例子，希望大家能夠喜歡。