【QT】SQLite 数据库案例——学生成绩管理系统

案例——学习成绩管理系统

• student-management.pro

  QT       += core gui sql
  
  greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
  
  CONFIG += c++11
  
  SOURCES += \
      main.cpp \
      dialog.cpp
  
  HEADERS += \
      dialog.h
  
  FORMS += \
      dialog.ui
  

• dialog.ui

  
  <ui version="4.0">
   <class>Dialogclass>
   <widget class="QDialog" name="Dialog">
    <property name="geometry">
     <rect>
      <x>0x>
      <y>0y>
      <width>600width>
      <height>400height>
     rect>
    property>
    <property name="font">
     <font>
      <family>Inconsolatafamily>
      <pointsize>16pointsize>
     font>
    property>
    <property name="windowTitle">
     <string>学生成绩管理系统string>
    property>
    <layout class="QVBoxLayout" name="verticalLayout">
     <item>
      <layout class="QHBoxLayout" name="horizontalLayout">
       <item>
        <widget class="QComboBox" name="sortColumnComboBox">
         <item>
          <property name="text">
           <string>idstring>
          property>
         item>
         <item>
          <property name="text">
           <string>scorestring>
          property>
         item>
        widget>
       item>
       <item>
        <widget class="QComboBox" name="sortTypeComboBox">
         <item>
          <property name="text">
           <string>ASCstring>
          property>
         item>
         <item>
          <property name="text">
           <string>DESCstring>
          property>
         item>
        widget>
       item>
       <item>
        <widget class="QPushButton" name="sortButton">
         <property name="text">
          <string>排序string>
         property>
        widget>
       item>
      layout>
     item>
     <item>
      <widget class="QTableView" name="tableView"/>
     item>
     <item>
      <layout class="QGridLayout" name="gridLayout">
       <item row="0" column="0">
        <widget class="QLabel" name="idLabel">
         <property name="text">
          <string>学生学号：string>
         property>
        widget>
       item>
       <item row="0" column="1">
        <widget class="QLineEdit" name="idEdit"/>
       item>
       <item row="1" column="0">
        <widget class="QLabel" name="nameLabel">
         <property name="text">
          <string>学生姓名：string>
         property>
        widget>
       item>
       <item row="1" column="1">
        <widget class="QLineEdit" name="nameEdit"/>
       item>
       <item row="2" column="0">
        <widget class="QLabel" name="scoreLabel">
         <property name="text">
          <string>学生成绩：string>
         property>
        widget>
       item>
       <item row="2" column="1">
        <widget class="QLineEdit" name="scoreEdit"/>
       item>
      layout>
     item>
     <item>
      <layout class="QHBoxLayout" name="horizontalLayout_2">
       <item>
        <widget class="QPushButton" name="insertButton">
         <property name="text">
          <string>插入string>
         property>
        widget>
       item>
       <item>
        <widget class="QPushButton" name="deleteButton">
         <property name="text">
          <string>删除string>
         property>
        widget>
       item>
       <item>
        <widget class="QPushButton" name="updateButton">
         <property name="font">
          <font>
           <family>Inconsolatafamily>
           <pointsize>16pointsize>
          font>
         property>
         <property name="text">
          <string>更新string>
         property>
        widget>
       item>
      layout>
     item>
    layout>
   widget>
   <resources/>
   <connections/>
  ui>
  

• dialog.h

  #ifndef DIALOG_H
  #define DIALOG_H
  
  #include 
  #include 
  #include 
  #include 
  #include 
  #include 
  
  QT_BEGIN_NAMESPACE
  namespace Ui { class Dialog; }
  QT_END_NAMESPACE
  
  class Dialog : public QDialog {
  Q_OBJECT
  public:
      Dialog(QWidget* parent = nullptr);
      ~Dialog();
  private slots:
      void on_insertButton_clicked();
      void on_deleteButton_clicked();
      void on_updateButton_clicked();
      void on_sortButton_clicked();
  private:
      void createDB();
      void createTable();
      void queryTable();
  private:
      Ui::Dialog* ui;
      QSqlDatabase db;
  };
  
  #endif // DIALOG_H
  

• dialog.cpp

  #include "dialog.h"
  #include "ui_dialog.h"
  
  Dialog::Dialog(QWidget* parent) : QDialog(parent), ui(new Ui::Dialog) {
      ui->setupUi(this);
      createDB();
      createTable();
      queryTable();
  }
  
  Dialog::~Dialog() {
      delete ui;
  }
  
  void Dialog::on_insertButton_clicked() {
      int id = ui->idEdit->text().toInt();
      if (id == 0) {
          QMessageBox::critical(this, "Error", "学号输入错误");
          return;
      }
      QString name = ui->nameEdit->text();
      if (name == "") {
          QMessageBox::critical(this, "Error", "姓名输入错误");
          return;
      }
      double score = ui->scoreEdit->text().toDouble();
      if (score < 0 || score > 100) {
          QMessageBox::critical(this, "Error", "成绩输入错误");
          return;
      }
      QString sql = QString("INSERT INTO student(id, name, score) VALUES(%1, '%2', %3)").arg(id).arg(name).arg(score);
      QSqlQuery query(db);
      if (!query.exec(sql)) {
          qDebug() << sql << query.lastError();
      } else {
          qDebug() << "插入数据成功";
          queryTable();
      }
  }
  
  void Dialog::on_deleteButton_clicked() {
      int id = ui->idEdit->text().toInt();
      QString sql = "DELETE FROM student WHERE id = :id";
      QSqlQuery query(db);
      query.prepare(sql);
      query.bindValue(":id", id);
      if (!query.exec()) {
          qDebug() << sql << query.lastError();
      } else {
          qDebug() << "删除数据成功";
          queryTable();
      }
  }
  
  void Dialog::on_updateButton_clicked() {
      int id = ui->idEdit->text().toInt();
      if (id == 0) {
          QMessageBox::critical(this, "Error", "学号输入错误");
          return;
      }
      double score = ui->scoreEdit->text().toDouble();
      if (score < 0 || score > 100) {
          QMessageBox::critical(this, "Error", "成绩输入错误");
          return;
      }
      QString sql = "UPDATE student SET score = :score WHERE id = :id";
      QSqlQuery query(db);
      query.prepare(sql);
      query.bindValue(":id", id);
      query.bindValue(":score", score);
      if (!query.exec()) {
          qDebug() << sql << query.lastError();
      } else {
          qDebug() << "更新数据成功";
          queryTable();
      }
  }
  
  void Dialog::on_sortButton_clicked() {
      QString sortColumn = ui->sortColumnComboBox->currentText();
      QString sortType = ui->sortTypeComboBox->currentText();
      QString sql = QString("SELECT * FROM student ORDER BY %1 %2").arg(sortColumn).arg(sortType);
      QSqlQueryModel* model = new QSqlQueryModel();
      model->setQuery(sql, db);
      ui->tableView->setModel(model);
  }
  
  void Dialog::createDB() {
      // 添加数据库驱动
      db = QSqlDatabase::addDatabase("QSQLITE");
      // 设置库名(文件名)
      db.setDatabaseName("student.db");
      // 打开数据库
      if (!db.open()) {
          qDebug() << "创建/打开数据库失败";
      } else {
          qDebug() << "创建/打开数据库成功";
      }
  }
  
  void Dialog::createTable() {
      QString sql = QString(
          "CREATE TABLE student ("
          "id    INT NOT NULL PRIMARY KEY,"
          "name  TEXT NOT NULL,"
          "score REAL NOT NULL"
          ")"
      );
      QSqlQuery query(db);
      if (!query.exec(sql)) {
          qDebug() << sql << query.lastError();
      } else {
          qDebug() << "建表成功";
      }
  }
  
  void Dialog::queryTable() {
      QString sql = "SELECT * FROM student";
      QSqlQueryModel* model = new QSqlQueryModel();
      model->setQuery(sql, db);
      ui->tableView->setModel(model);
  }
  

  效果