Qt 自带的数据库QSQLITE

database.h

 1 #ifndef DATABASE_H
 2 #define DATABASE_H
 3 
 4 #include <QTextCodec>
 5 #include <QSqlDatabase>
 6 #include <QSqlQuery>
 7 #include <QTime>
 8 #include <QSqlError>
 9 #include <QtDebug>
10 #include <QSqlDriver>
11 #include <QSqlRecord>
12 
13 class DataBase
14 {
15 public:
16     bool createConnection();  //创建一个连接
17     bool createTable();       //创建数据库表
18     bool insert();            //出入数据
19     bool queryAll();          //查询所有信息
20     bool updateById(int id);  //更新
21     bool deleteById(int id);  //删除
22     bool sortById();          //排序
23 };
24 
25 #endif // DATABASE_H

database.cpp

  1 #include "database.h"
  2 
  3 
  4 //建立一个数据库连接
  5 bool DataBase::createConnection()
  6 {
  7     //以后就可以用"sqlite1"与数据库进行连接了
  8     QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE", "sqlite1");
  9     db.setDatabaseName(".//qtDb.db");
 10     if( !db.open())
 11     {
 12         qDebug() << "无法建立数据库连接";
 13         return false;
 14     }
 15     return true;
 16 }
 17 
 18 //创建数据库表
 19 bool DataBase::createTable()
 20 {
 21     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
 22     QSqlQuery query(db);
 23     bool success = query.exec("create table automobil(id int primary key,attribute varchar,"
 24                               "type varchar,kind varchar,nation int,carnumber int,elevaltor int,"
 25                               "distance int,oil int,temperature int)");
 26     if(success)
 27     {
 28         qDebug() << QObject::tr("数据库表创建成功！\n");
 29         return true;
 30     }
 31     else
 32     {
 33         qDebug() << QObject::tr("数据库表创建失败！\n");
 34         return false;
 35     }
 36 }
 37 
 38 //向数据库中插入记录
 39 bool DataBase::insert()
 40 {
 41     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
 42     QSqlQuery query(db);
 43     query.prepare("insert into automobil values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
 44 
 45     long records = 10;
 46     for(int i=0; i<records; i++)
 47     {
 48         query.bindValue(0, i);
 49         query.bindValue(1, "四轮");
 50         query.bindValue(2, "轿车");
 51         query.bindValue(3, "富康");
 52         query.bindValue(4, rand()%100);
 53         query.bindValue(5, rand()%10000);
 54         query.bindValue(6, rand()%300);
 55         query.bindValue(7, rand()%200000);
 56         query.bindValue(8, rand()%52);
 57         query.bindValue(9, rand()%100);
 58 
 59         bool success=query.exec();
 60         if(!success)
 61         {
 62             QSqlError lastError = query.lastError();
 63             qDebug() << lastError.driverText() << QString(QObject::tr("插入失败"));
 64             return false;
 65         }
 66     }
 67     return true;
 68 }
 69 
 70 //查询所有信息
 71 bool DataBase::queryAll()
 72 {
 73     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
 74     QSqlQuery query(db);
 75     query.exec("select * from automobil");
 76     QSqlRecord rec = query.record();
 77     qDebug() << QObject::tr("automobil表字段数：" ) << rec.count();
 78 
 79     while(query.next())
 80     {
 81         for(int index = 0; index < 10; index++)
 82             qDebug() << query.value(index) << " ";
 83         qDebug() << "\n";
 84     }
 85 }
 86 
 87 //根据ID删除记录
 88 bool DataBase::deleteById(int id)
 89 {
 90     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
 91     QSqlQuery query(db);
 92     query.prepare(QString("delete from automobil where id = %1").arg(id));
 93     if(!query.exec())
 94     {
 95         qDebug() << "删除记录失败！";
 96         return false;
 97     }
 98     return true;
 99 }
100 
101 //根据ID更新记录
102 bool DataBase::updateById(int id)
103 {
104     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
105     QSqlQuery query(db);
106     query.prepare(QString("update automobil set attribute=?,type=?,"
107                              "kind=?, nation=?,"
108                              "carnumber=?, elevaltor=?,"
109                              "distance=?, oil=?,"
110                              "temperature=? where id=%1").arg(id));
111 
112      query.bindValue(0,"四轮");
113      query.bindValue(1,"轿车");
114      query.bindValue(2,"富康");
115      query.bindValue(3,rand()%100);
116      query.bindValue(4,rand()%10000);
117      query.bindValue(5,rand()%300);
118      query.bindValue(6,rand()%200000);
119      query.bindValue(7,rand()%52);
120      query.bindValue(8,rand()%100);
121 
122      bool success=query.exec();
123      if(!success)
124      {
125           QSqlError lastError = query.lastError();
126           qDebug() << lastError.driverText() << QString(QObject::tr("更新失败"));
127      }
128     return true;
129 }
130 
131 //排序
132 bool DataBase::sortById()
133 {
134     QSqlDatabase db = QSqlDatabase::database("sqlite1"); //建立数据库连接
135     QSqlQuery query(db);
136     bool success=query.exec("select * from automobil order by id desc");
137     if(success)
138     {
139         qDebug() << QObject::tr("排序成功");
140         return true;
141     }
142     else
143     {
144         qDebug() << QObject::tr("排序失败！");
145         return false;
146     }
147 }

main.cpp

 1 #include <QCoreApplication>
 2 #include "database.h"
 3 
 4 int main(int argc, char *argv[])
 5 {
 6     QCoreApplication a(argc, argv);
 7     QTextCodec::setCodecForLocale(QTextCodec::codecForLocale());
 8 
 9     DataBase d;
10     d.createConnection();  //创建连接
11     //d.createTable();
12     //d.insert();
13     d.queryAll();          //已经完成过createTable(), insert(), 现在进行查询
14 
15     return 0;
16 }

运行结果

这里写图片描述

项目名称为”sqlex”，然后就可以在与当前项目同一级目录下的“build-SQLEx-Desktop_Qt_5_7_0_MinGW_32bit-Debug”中可以看到qtDb.db数据库文件，该数据库可以用软件SQLite直接打开

posted on 2021-02-03 15:18 一杯清酒邀明月阅读(796) 评论(0) 编辑收藏举报