1、整体界面效果

2、条目UI设计

2.1 自定义条目字段：ID、名字、年龄、地址、薪水

2.2 条目类相关代码

***************************************源文件***********************************************
#include "itemform.h"
#include "ui_itemform.h"

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

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

void itemForm::setStaffInfo(int id, QString name, int age, QString addr, int salary)
{
    ui->label_ID->setText(QString::number(id));
    ui->label_name->setText(name);
    ui->label_age->setText(QString::number(age));
    ui->label_address->setText(addr);
    ui->label_salary->setText(QString::number(salary));
}

*******************************************头文件*******************************************
#ifndef ITEMFORM_H
#define ITEMFORM_H

#include <QMainWindow>

namespace Ui {
class itemForm;
}

class itemForm : public QMainWindow
{
    Q_OBJECT

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

    void setStaffInfo(int id,QString name,int age,QString addr,int salary);

private:
    Ui::itemForm *ui;
};

#endif // ITEMFORM_H

3、主界面UI设计

3.1 自定义基本的数据操作：添加、更新、删除、查询

3.2 主界面类相关代码

**************************************源文件*********************************************
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QString>
MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    //step1：根据数据库的类型，链接数据
    db=QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName("compary.db");
    //step2：打开数据库
    if(!db.open()){
        qDebug()<<"open error..."<<db.lastError();
    }
    //step3：根据需求，创建数据库所需要的表
    QSqlQuery query;
    /**
     * @brief sqlCreateTable
     * 字段名：id name age address salary
     */
 #if 0
    QString sqlCreateTable=QString("create table staff(id integer primary key autoincrement,"
                                   "name varchar(20),"
                                   "age int,"
                                   "address varchar(50),"
                                   "salary int)");
    if(!query.exec(sqlCreateTable)){
        qDebug()<<"create table error"<<db.lastError();
    }

#endif


}

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


void MainWindow::on_addBtn_clicked()
{
    //获取UI控件上的内容
    QString name=ui->lineEdit_name->text();
    QString salary=ui->lineEdit_salary->text();
    QString address=ui->lineEdit_address->text();
    QString age=ui->lineEdit_age->text();

    QSqlQuery query;


    //插入数据操作
    QString sqlInsert=QString("insert into staff(name,age,address,salary) values('%1',%2,'%3',%4);").arg(name)
            .arg(age.toInt())
            .arg(address)
            .arg(salary.toInt());

    if(!query.exec(sqlInsert)){
        qDebug()<<"insert data error..."<<db.lastError();
    }else{
        qDebug()<<"Insert data success..."<<endl;
    }

    on_selectBtn_clicked();

}

void MainWindow::on_updateBtn_clicked()
{
    QSqlQuery query;

    QString id=ui->lineEdit_ID->text();
    QString address=ui->lineEdit_address->text();
    //更新数据操作
    QString sqlUpdate=QString("update staff set address = '%1' where id = %2;").arg(address)
            .arg(id.toInt());


    if(!query.exec(sqlUpdate)){
        qDebug()<<"Update data error..."<<db.lastError();
    }else{
        qDebug()<<"Update data success..."<<endl;
    }
    on_selectBtn_clicked();
}

void MainWindow::on_deleteBtn_clicked()
{
    QSqlQuery query;

    QString id=ui->lineEdit_ID->text();
    //删除操作
    QString sqlDelete=QString("delete from staff where id='%1';").arg(id.toInt());


    if(!query.exec(sqlDelete)){
        qDebug()<<"Delete data error..."<<db.lastError();
    }else{
        qDebug()<<"Delete data success...";
    }

    on_selectBtn_clicked();
}

void MainWindow::on_selectBtn_clicked()
{
    //查询数据之前清空列表上的内容
    ui->listWidget->clear();
    //查询数据操作
    QSqlQuery query;

    QString sqlSelect=QString("select * from staff;");

    if(!query.exec(sqlSelect)){
        qDebug()<<"Select data error..."<<db.lastError();
    }else{
        //遍历数据库记录
        while(query.next()){
            int id=query.value("id").toInt();
            QString name=query.value("name").toString();
            int age=query.value("age").toInt();
            QString address=query.value("address").toString();
            int salary=query.value("salary").toInt();

            qDebug()<<"id = "<<id<<", name = "<<name<<", age = "<<age<<", address = "<<address<<", salary = "<<salary;
            //每遍历一条记录，就要更新在UI控件上
            itemForm* staffitem=new itemForm;
            staffitem->setStaffInfo(id,name,age,address,salary);
            QListWidgetItem* item=new QListWidgetItem;
            item->setSizeHint(QSize(624,55));
            ui->listWidget->addItem(item);
            ui->listWidget->setItemWidget(item,staffitem);
        }

    }
}

**************************************头文件*********************************************
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QSqlDatabase>
#include <QDebug>
#include <QSqlQuery>
#include <QSqlError>
#include "itemform.h"
#include <QListWidgetItem>
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 on_addBtn_clicked();

    void on_updateBtn_clicked();

    void on_deleteBtn_clicked();

    void on_selectBtn_clicked();

private:
    Ui::MainWindow *ui;
    QSqlDatabase db;
};
#endif // MAINWINDOW_H



*************************************主函数***********************************************
#include "mainwindow.h"

#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}