利用QT+Sqlite数据库编写简易的学生信息管理系统

1.编辑ui

SqliteQtDialog.h

2.添加头文件

#include <QDialog>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlError>
#include <QMessageBox>
#include <QSqlQueryModel>
#include <QDebug>

3.添加函数声明

private slots:
    void on_insertButton_clicked();
    void on_deleteButton_clicked();
    void on_modifyButton_clicked();
    void on_sortButton_clicked();
private:
    void createDB(void);//创建数据库
    void createTable(void);//创建学生成绩表
    void queryTable(void);//查询数据表
private:
    Ui::SqliteQtDialog *ui;
    QSqlDatabase db;//建立和qt和数据库连接
    QSqlQueryModel model;//保存和遍历select结果

SqliteQtDialog.cpp

4.添加函数

#include "SqliteQtDialog.h"
#include "ui_SqliteQtDialog.h"

SqliteQtDialog::SqliteQtDialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::SqliteQtDialog)
{
    ui->setupUi(this);
    createDB();
    createTable();
    //查询和显示
    queryTable();
}

SqliteQtDialog::~SqliteQtDialog()
{
    delete ui;
}
void SqliteQtDialog::createDB(void){//创建数据库
    //建立和SQlite数据库连接
    db = QSqlDatabase::addDatabase("QSQLITE");
    //设置数据库文件的名称
    db.setDatabaseName("menu.db");
    //打开数据库
    if(db.open() == false){
        QMessageBox::critical(this,"DataError",
                              db.lastError().text());
    }
}
void SqliteQtDialog::createTable(void){//创建表
    //构建创建表的SQL语句
    QString createSql =
            QString("CREATE TABLE Student(\
                id INT PRIMARY KEY NOT NULL,\
                name TEXT NOT NULL,\
                score REAL NOT NULL)");
     QSqlQuery query;
     query.exec(createSql);

}
void SqliteQtDialog::queryTable(void){//查询表
    QString str = QString("SELECT * FROM Student");
    model.setQuery(str);
    ui->tableView->setModel(&model);
}
void SqliteQtDialog::on_insertButton_clicked()
{
    QSqlQuery query;
    //获取学号
    int id = ui->idEdit->text().toInt();
    //获取姓名
    QString name(ui->nameEdit->text());
    //获取成绩
    double score = ui->scoreEdit->text().toDouble();
    //构造sql语句
    QString insertSql = QString(
        "INSERT INTO Student VALUES(%1,'%2',%3);"
                ).arg(id).arg(name).arg(score);
    qDebug() << insertSql;
    //执行sql语句
    query.exec(insertSql);
    query.exec("commit");
    //查询和显示
    queryTable();
}
//删除，通过ID匹配
void SqliteQtDialog::on_deleteButton_clicked()
{
    int id = ui->idEdit->text().toInt();
    //构造删除sql语句
    QString deleteSql = QString(
        "DELETE FROM Student WHERE id=%1").arg(id);
    QSqlQuery query;
    query.exec(deleteSql);
    //查询和显示
    queryTable();
}
//修改成绩
void SqliteQtDialog::on_modifyButton_clicked()
{
    QSqlQuery query;
    int id = ui->idEdit->text().toInt();
    double score = ui->scoreEdit->text().toDouble();
    QString modifySql = QString(
        "UPDATE Student SET score=%1 WHERE id=%2").
            arg(score).arg(id);
    qDebug() << modifySql;
    query.exec(modifySql);
    //查询和显示
    queryTable();
}
//排序
void SqliteQtDialog::on_sortButton_clicked()
{
    //获取排序关键字
    QString value = ui->ValueComboBox->currentText();
    //获取排序条件
    QString condition;
    if(ui->CondComboBox->currentIndex()){
        condition = "DESC";
    }
    else{
        condition = "ASC";
    }
    QString sortSql = QString(
        "SELECT * FROM Student ORDER BY %1 %2").
            arg(value).arg(condition);
    model.setQuery(sortSql);
    ui->tableView->setModel(&model);
}

5.效果