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這篇文章主要講解了“Qt怎么連接數(shù)據(jù)庫并實(shí)現(xiàn)數(shù)據(jù)庫增刪改查”,文中的講解內(nèi)容簡單清晰,易于學(xué)習(xí)與理解,下面請(qǐng)大家跟著小編的思路慢慢深入,一起來研究和學(xué)習(xí)“Qt怎么連接數(shù)據(jù)庫并實(shí)現(xiàn)數(shù)據(jù)庫增刪改查”吧!
先來看下連接數(shù)據(jù)庫的效果圖。
“連接數(shù)據(jù)庫”按鈕的槽函數(shù)如下:
void MainWindow::on_pushButton_connectDataBase_clicked() { //連接數(shù)據(jù)庫 db.setHostName("127.0.0.1"); db.setPort(3306); db.setDatabaseName("test");//數(shù)據(jù)庫名稱 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)庫連接成功"); qDebug()<<"數(shù)據(jù)庫連接成功"; } else { QMessageBox::information(this, "提示","數(shù)據(jù)庫連接失敗"); this->close(); qDebug()<<"數(shù)據(jù)庫連接失敗"; } //若數(shù)據(jù)庫中沒有表,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)庫名等信息沒有填錯(cuò)的情況下,數(shù)據(jù)庫連接失敗,并打印以下信息,情參考該鏈接解決:http://www.kemok4.com/article/281192.htm
當(dāng)運(yùn)行點(diǎn)擊"連接數(shù)據(jù)庫"按鈕后,會(huì)根據(jù)信息連接對(duì)應(yīng)的數(shù)據(jù)庫,若連接的該數(shù)據(jù)庫沒有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。
先看下效果圖:
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); }
先看添加的效果圖:
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(); }
修改的效果圖:
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(); }
刪除的效果圖:
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"); }
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 db.setHostName("127.0.0.1"); db.setPort(3306); db.setDatabaseName("test");//數(shù)據(jù)庫名稱 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)庫連接成功"); qDebug()<<"數(shù)據(jù)庫連接成功"; } else { QMessageBox::information(this, "提示","數(shù)據(jù)庫連接失敗"); this->close(); qDebug()<<"數(shù)據(jù)庫連接失敗"; } //若數(shù)據(jù)庫中沒有表,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); }
感謝各位的閱讀,以上就是“Qt怎么連接數(shù)據(jù)庫并實(shí)現(xiàn)數(shù)據(jù)庫增刪改查”的內(nèi)容了,經(jīng)過本文的學(xué)習(xí)后,相信大家對(duì)Qt怎么連接數(shù)據(jù)庫并實(shí)現(xiàn)數(shù)據(jù)庫增刪改查這一問題有了更深刻的體會(huì),具體使用情況還需要大家實(shí)踐驗(yàn)證。這里是億速云,小編將為大家推送更多相關(guān)知識(shí)點(diǎn)的文章,歡迎關(guān)注!
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