Qt連接數(shù)據(jù)庫(kù)并實(shí)現(xiàn)數(shù)據(jù)庫(kù)增刪改查的圖文教程

更新時(shí)間：2023年04月15日 10:14:17 作者：小趙的學(xué)習(xí)之路

QT連接數(shù)據(jù)庫(kù)是應(yīng)用開發(fā)的常用基礎(chǔ)操作,經(jīng)過(guò)實(shí)驗(yàn)我總結(jié)了一些例程,下面這篇文章主要給大家介紹了關(guān)于Qt連接數(shù)據(jù)庫(kù)并實(shí)現(xiàn)數(shù)據(jù)庫(kù)增刪改查的相關(guān)資料,文中通過(guò)實(shí)例代碼介紹的非常詳細(xì),需要的朋友可以參考下

1.連接數(shù)據(jù)庫(kù)

先來(lái)看下連接數(shù)據(jù)庫(kù)的效果圖。

“連接數(shù)據(jù)庫(kù)”按鈕的槽函數(shù)如下：

void MainWindow::on_pushButton_connectDataBase_clicked()
{
    //連接數(shù)據(jù)庫(kù)
    db.setHostName("127.0.0.1");
    db.setPort(3306);
    db.setDatabaseName("test");//數(shù)據(jù)庫(kù)名稱
    db.setUserName("root");//用戶名
    db.setPassword("root");//密碼

    qDebug()<<"available drivers:";
    QStringList drivers = QSqlDatabase::drivers();
    for(auto driver: drivers)
        qDebug() << driver;
    bool ok = db.open();
    if(ok)
    {
        QMessageBox::information(this, "提示","數(shù)據(jù)庫(kù)連接成功");
        qDebug()<<"數(shù)據(jù)庫(kù)連接成功";
    }
    else
    {
        QMessageBox::information(this, "提示","數(shù)據(jù)庫(kù)連接失敗");
        this->close();
        qDebug()<<"數(shù)據(jù)庫(kù)連接失敗";
    }

    //若數(shù)據(jù)庫(kù)中沒(méi)有表，則新建
    QSqlQuery query;
    QString createTableUser="create table if not exists user(name varchar(8),age int(255), "
                           "sex varchar(8), number int(255));";
    query.exec(createTableUser);
}

若在數(shù)據(jù)庫(kù)名等信息沒(méi)有填錯(cuò)的情況下，數(shù)據(jù)庫(kù)連接失敗，并打印以下信息，情參考該鏈接解決：http://www.dbjr.com.cn/article/281192.htm

當(dāng)運(yùn)行點(diǎn)擊"連接數(shù)據(jù)庫(kù)"按鈕后，會(huì)根據(jù)信息連接對(duì)應(yīng)的數(shù)據(jù)庫(kù)，若連接的該數(shù)據(jù)庫(kù)沒(méi)有user表時(shí)，會(huì)自動(dòng)創(chuàng)建一個(gè)user表，創(chuàng)建的表信息如下圖所示，該圖為Navicat Premium 15軟件內(nèi)的截圖。

2.查詢數(shù)據(jù)庫(kù)并顯示在QTableView上

先看下效果圖：

請(qǐng)?zhí)砑訄D片描述

首先定義一個(gè)QSqlQueryModel數(shù)據(jù)模型，并于對(duì)應(yīng)的QTableView綁定，如下：

QSqlQueryModel *userMode;//數(shù)據(jù)模型
userMode = new QSqlQueryModel(ui->tableView);//綁定

設(shè)置點(diǎn)擊查詢的槽函數(shù)：

//查詢
void MainWindow::on_pushButton_query_clicked()
{
    userMode->setQuery("select * from user;");
    ReshowTable();
}
void MainWindow::ReshowTable()
{
    userMode->setHeaderData(0,Qt::Horizontal,tr("姓名"));
    userMode->setHeaderData(1,Qt::Horizontal,tr("年齡"));
    userMode->setHeaderData(2,Qt::Horizontal,tr("性別"));
    userMode->setHeaderData(3,Qt::Horizontal,tr("手機(jī)號(hào)"));
    ui->tableView->setModel(userMode);
}

3.添加

先看添加的效果圖：

請(qǐng)?zhí)砑訄D片描述

在信息輸入內(nèi)對(duì)應(yīng)填寫各信息，填寫完成后點(diǎn)擊“添加”按鈕，可添加完成輸入的對(duì)應(yīng)信息，與數(shù)據(jù)庫(kù)內(nèi)容同步，添加按鈕的槽函數(shù)：

//添加
void MainWindow::on_pushButton_add_clicked()
{
    QString name = ui->lineEdit_name->text();
    QString age = ui->lineEdit_age->text();
    QString sex = ui->lineEdit_sex->text();
    QString number = ui->lineEdit_number->text();
    QSqlQuery query;
    QString str1 = "'" + name +"','" + age + "','" +sex+"','"+number+"'";
    QString str = "insert into user(name, age, sex, number) values(" + str1 + ");";
    query.exec(str);
    userMode->setQuery("select * from user;");
    ReshowTable();
}

4.修改

修改的效果圖：

請(qǐng)?zhí)砑訄D片描述

設(shè)置點(diǎn)擊表格中的某一列，然后將點(diǎn)擊那一列的信息顯示在編輯信息的文本框內(nèi)，修改完成后點(diǎn)擊修改即可完成修改，對(duì)應(yīng)函數(shù)如下函數(shù)：

void MainWindow::on_tableView_pressed(const QModelIndex &index)
{
    QString name = userMode->data(userMode->index(index.row(), 0)).toString();
    QString age = userMode->data(userMode->index(index.row(), 1)).toString();
    QString sex = userMode->data(userMode->index(index.row(), 2)).toString();
    QString number = userMode->data(userMode->index(index.row(), 3)).toString();

    ui->lineEdit_name->setText(name);
    ui->lineEdit_age->setText(age);
    ui->lineEdit_sex->setText(sex);
    ui->lineEdit_number->setText(number);
}
//修改
void MainWindow::on_pushButton_change_clicked()
{
    QSqlQuery query;
    QString str = "update user set name='" + ui->lineEdit_name->text() + "',age='" + ui->lineEdit_age->text() + "',sex='" + ui->lineEdit_sex->text() + "' where number='" + ui->lineEdit_number->text() + "';";
    query.exec(str);
    QMessageBox::information(this, "修改成功", "表信息修改成功");
    userMode->setQuery("select * from user;");
    ReshowTable();
}

5.刪除

刪除的效果圖：

請(qǐng)?zhí)砑訄D片描述

刪除的槽函數(shù)如下：

//刪除
void MainWindow::on_pushButton_delete_clicked()
{
    QSqlQuery query;
    int currentrow = ui->tableView->currentIndex().row();
    userMode->removeRow(currentrow);
    if(currentrow != -1)//若選中一行
    {
        int ok  =  QMessageBox::warning(this,tr("刪除當(dāng)前行!"),tr("你確定刪除當(dāng)前行嗎？"), QMessageBox::Yes,QMessageBox::No);
        //如確認(rèn)刪除
        if(ok == QMessageBox::Yes)
        {
            userMode->removeRow(currentrow);
            QString name = userMode->data(userMode->index(currentrow,0)).toString();//獲取姓名
            QString del = "delete from user where name='" + name + "';";
            query.exec(del);
            userMode->setQuery("select * from user");
            ui->tableView->setModel(userMode);
            QMessageBox::information(this, "刪除成功", "所選信息刪除成功");
        }
    }
    else
        QMessageBox::information(this, "提示", "請(qǐng)選擇你要?jiǎng)h除的信息行");
}

6.總代碼

mainwidow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QMessageBox>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QDebug>
#include <QSqlQueryModel>

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void ReshowTable();

    void on_pushButton_connectDataBase_clicked();

    void on_pushButton_add_clicked();

    void on_pushButton_delete_clicked();

    void on_pushButton_change_clicked();

    void on_pushButton_query_clicked();

    void on_tableView_pressed(const QModelIndex &index);

private:
    Ui::MainWindow *ui;
    QSqlDatabase db= QSqlDatabase::addDatabase("QMYSQL");

    QSqlQueryModel *userMode;//數(shù)據(jù)模型

};
#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

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

    userMode = new QSqlQueryModel(ui->tableView);//綁定
}

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

void MainWindow::ReshowTable()
{
    userMode->setHeaderData(0,Qt::Horizontal,tr("姓名"));
    userMode->setHeaderData(1,Qt::Horizontal,tr("年齡"));
    userMode->setHeaderData(2,Qt::Horizontal,tr("性別"));
    userMode->setHeaderData(3,Qt::Horizontal,tr("手機(jī)號(hào)"));
    ui->tableView->setModel(userMode);
}

void MainWindow::on_pushButton_connectDataBase_clicked()
{
    //連接數(shù)據(jù)庫(kù)
    db.setHostName("127.0.0.1");
    db.setPort(3306);
    db.setDatabaseName("test");//數(shù)據(jù)庫(kù)名稱
    db.setUserName("root");//用戶名
    db.setPassword("root");//密碼

    qDebug()<<"available drivers:";
    QStringList drivers = QSqlDatabase::drivers();
    for(auto driver: drivers)
        qDebug() << driver;
    bool ok = db.open();
    if(ok)
    {
        QMessageBox::information(this, "提示","數(shù)據(jù)庫(kù)連接成功");
        qDebug()<<"數(shù)據(jù)庫(kù)連接成功";
    }
    else
    {
        QMessageBox::information(this, "提示","數(shù)據(jù)庫(kù)連接失敗");
        this->close();
        qDebug()<<"數(shù)據(jù)庫(kù)連接失敗";
    }

    //若數(shù)據(jù)庫(kù)中沒(méi)有表，則新建
    QSqlQuery query;
    QString createTableUser="create table if not exists user(name varchar(8),age int(255), "
                           "sex varchar(8), number int(255));";
    query.exec(createTableUser);
}

//添加
void MainWindow::on_pushButton_add_clicked()
{
    QString name = ui->lineEdit_name->text();
    QString age = ui->lineEdit_age->text();
    QString sex = ui->lineEdit_sex->text();
    QString number = ui->lineEdit_number->text();
    QSqlQuery query;
    QString str1 = "'" + name +"','" + age + "','" +sex+"','"+number+"'";
    QString str = "insert into user(name, age, sex, number) values(" + str1 + ");";
    query.exec(str);
    userMode->setQuery("select * from user;");
    ReshowTable();
}
//刪除
void MainWindow::on_pushButton_delete_clicked()
{
    QSqlQuery query;
    int currentrow = ui->tableView->currentIndex().row();
    userMode->removeRow(currentrow);
    if(currentrow != -1)//若選中一行
    {
        int ok  =  QMessageBox::warning(this,tr("刪除當(dāng)前行!"),tr("你確定刪除當(dāng)前行嗎？"), QMessageBox::Yes,QMessageBox::No);
        //如確認(rèn)刪除
        if(ok == QMessageBox::Yes)
        {
            userMode->removeRow(currentrow);
            QString name = userMode->data(userMode->index(currentrow,0)).toString();//獲取姓名
            QString del = "delete from user where name='" + name + "';";
            query.exec(del);
            userMode->setQuery("select * from user");
            ui->tableView->setModel(userMode);
            QMessageBox::information(this, "刪除成功", "所選信息刪除成功");
        }
    }
    else
        QMessageBox::information(this, "提示", "請(qǐng)選擇你要?jiǎng)h除的信息行");
}
//修改
void MainWindow::on_pushButton_change_clicked()
{
    QSqlQuery query;
    QString str = "update user set name='" + ui->lineEdit_name->text() + "',age='" + ui->lineEdit_age->text() + "',sex='" + ui->lineEdit_sex->text() + "' where number='" + ui->lineEdit_number->text() + "';";
    query.exec(str);
    QMessageBox::information(this, "修改成功", "表信息修改成功");
    userMode->setQuery("select * from user;");
    ReshowTable();
}
//查詢
void MainWindow::on_pushButton_query_clicked()
{
    userMode->setQuery("select * from user;");
    ReshowTable();
}

void MainWindow::on_tableView_pressed(const QModelIndex &index)
{
    QString name = userMode->data(userMode->index(index.row(), 0)).toString();
    QString age = userMode->data(userMode->index(index.row(), 1)).toString();
    QString sex = userMode->data(userMode->index(index.row(), 2)).toString();
    QString number = userMode->data(userMode->index(index.row(), 3)).toString();

    ui->lineEdit_name->setText(name);
    ui->lineEdit_age->setText(age);
    ui->lineEdit_sex->setText(sex);
    ui->lineEdit_number->setText(number);
}

總結(jié)

到此這篇關(guān)于Qt連接數(shù)據(jù)庫(kù)并實(shí)現(xiàn)數(shù)據(jù)庫(kù)增刪改查的文章就介紹到這了,更多相關(guān)Qt連接數(shù)據(jù)庫(kù)并增刪改查內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

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