【1】sqlite3_test1.pro

添加sql

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【2】mainwindow.ui

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【3】mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
//   2022-11-5
typedef struct SQL_DATA{QString car_id;             /* 车牌号 */QString car_pos;            /* 车位号 */QString card_id;           /* 卡号 */int age;                   /* 人脸特征数据大小 */QByteArray t_featuredata; /* 人脸特征数据 */QString t_datetime;       /* 存车时间 */
} SQL_DATA_TypeDef;
/*Q_DECLARE_METATYPE ->这个宏只要提供公共默认构造函数、公共复制构造函数。需要在QVariant中使用类型作为自定义类型。*/
Q_DECLARE_METATYPE(SQL_DATA)class MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();private slots:void on_pushButton_clicked();void on_pushButton_2_clicked();void on_pushButton_6_clicked();void on_pushButton_3_clicked();void on_pushButton_7_clicked();void on_pushButton_4_clicked();void on_pushButton_5_clicked();private:Ui::MainWindow *ui;QSqlDatabase db1;QSqlDatabase db2;QSqlQuery *que;QSqlRecord rec;
};
#endif // MAINWINDOW_H

【4】mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);//ZH_CHINAQTextCodec *codec = QTextCodec::codecForName("UTF-8");QTextCodec::setCodecForLocale(codec);
}MainWindow::~MainWindow()
{delete ui;
}
//create database
void MainWindow::on_pushButton_6_clicked()
{db1.removeDatabase("RB");//every create database daletedb1 = QSqlDatabase::addDatabase("QSQLITE","RB");db1.setDatabaseName("1.db");bool ret = db1.open();if(ret == true)ui->textEdit->append("open 1.db sucess");elseui->textEdit->append(db1.lastError().text());que = new QSqlQuery(db1);
}
//create table
void MainWindow::on_pushButton_2_clicked()
{if(que->exec("drop table if exists rb_tab1;"))ui->textEdit->append("drop table sucess");elseui->textEdit->append(que->lastError().text());bool t =que->exec("create table if not exists rb_tab1(id integer ,name text,height real);");if(!t) ui->textEdit->append(que->lastError().text());else ui->textEdit->append("create table rb_tab1 sucess");
}
//insert data
void MainWindow::on_pushButton_clicked()
{QString str = QString("insert into rb_tab1 values(10086,'TDM',18.99);");if(!que->exec(str)) ui->textEdit->append(que->lastError().text());else ui->textEdit->append("insert  rb_tab1 sucess");
}
//select data
void MainWindow::on_pushButton_3_clicked()
{QString str = QString("select *from rb_tab1;");if(que->exec(str)){ui->textEdit->append("select *from rb_tab1 sucessful;");}else{ui->textEdit->append(que->lastError().text());}//get [select *from rb_tab1] resultrec = que->record();//return data values countint count = rec.count();ui->textEdit->append(QString("table data tatol number =%1").arg(count));if(count == 3){while (que->next()) {ui->textEdit->append(QString("id =%1 \t name =%2 \t height =%3").arg(que->value(0).toInt()).arg(que->value(1).toString()).arg(que->value(2).toDouble()));}}else{while (que->next()) {ui->textEdit->append(QString("id =%1 \t name =%2 \t height =%3 \t card_id =%4").arg(que->value(0).toInt()).arg(que->value(1).toString()).arg(que->value(2).toDouble()).arg(que->value(3).toString()));}}
}
//show table values
void MainWindow::on_pushButton_7_clicked()
{QString str = QString("select *from rb_tab1;");if(que->exec(str)){ui->textEdit->append("select *from rb_tab1 sucessful;");}else{ui->textEdit->append(que->lastError().text());}//get [select *from rb_tab1] resultrec = que->record();//return data values countint count = rec.count();if(count == 3){ui->textEdit->append(QString("table data tatol number =%1").arg(count));while (que->next()) {ui->textEdit->append(QString("id =%1 \t name =%2 \t height =%3").arg(que->value(0).toInt()).arg(que->value(1).toString()).arg(que->value(2).toDouble()));}}else if(count == 4){ui->textEdit->append(QString("table data tatol number =%1").arg(count));while (que->next()) {ui->textEdit->append(QString("id =%1 \t name =%2 \t height =%3 \t char_id = %4").arg(que->value(0).toInt()).arg(que->value(1).toString()).arg(que->value(2).toDouble()).arg(que->value(3).toString()));}}
}
//update table values
void MainWindow::on_pushButton_4_clicked()
{int ret =que->exec("update rb_tab1 set id =200,name = 'NMD',height = 23.55;");if(ret){ui->textEdit->append("update table value sucessful");}else{ui->textEdit->append(que->lastError().text());}QString str = QString("select *from rb_tab1;");if(que->exec(str)){ui->textEdit->append("select *from rb_tab1 sucessful;");}else{ui->textEdit->append(que->lastError().text());}//get [select *from rb_tab1] resultrec = que->record();//return data values countint count = rec.count();if(count == 4){int ret =que->exec("update rb_tab1 set id =200,name = 'NMD',height = 23.55,card_id = '222222';");if(ret){ui->textEdit->append("update table value sucessful");}else{ui->textEdit->append(que->lastError().text());}}
}
//add new column
void MainWindow::on_pushButton_5_clicked()
{int ret =que->exec("alter table rb_tab1 add card_id char(18);");if(ret){ui->textEdit->append("alter table rb_tab1 add card_id char(18)");}else{ui->textEdit->append(que->lastError().text());}
}