數據庫

2019-11-08 20:07:30

字體：大中小

來源：轉載

供稿：網友

//例子1#include <QCoreapplication>#include <QTextCodec>#include <QSqlDatabase>#include <QSqlQuery>#include <QTime>#include <QSqlError>#include <QtDebug>#include <QSqlDriver>#include <QSqlRecord>int main(int argc, char *argv[]){ QCoreApplication a(argc, argv); QTextCodec::setCodecForLocale(QTextCodec::codecForLocale()); QSqlDatabase db =QSqlDatabase::addDatabase("QSQLITE"); //使用QSQLITE驅動 db.setHostName("easybook-3313b0"); //設置數據庫主機名 db.setDatabaseName("qtDB.db"); //設置數據庫名 db.setUserName("zhouhejun"); //設置數據庫用戶名 db.setPassWord("123456"); //設置數據庫密碼 db.open(); //打開連接 //創建數據庫表 QSqlQuery query; bool success=query.exec("create table automobil(id int PRimary key,attribute varchar,type varchar,kind varchar,nation int,carnumber int,elevaltor int,distance int,oil int,temperature int)"); if(success) qDebug()<<QObject::tr("數據庫表創建成功！/n"); else qDebug()<<QObject::tr("數據庫表創建失敗！/n"); //查詢 query.exec("select * from automobil"); QSqlRecord rec = query.record(); //查詢返回的記錄 qDebug() << QObject::tr("automobil表字段數：" )<< rec.count(); //插入記錄 QTime t; t.start(); query.prepare("insert into automobil values(?,?,?,?,?,?,?,?,?,?)"); long records=100; for(int i=0;i<records;i++) { //設置對應位置的參數 query.bindValue(0,i); query.bindValue(1,"四輪"); query.bindValue(2,"轎車"); query.bindValue(3,"富康"); query.bindValue(4,rand()%100); query.bindValue(5,rand()%10000); query.bindValue(6,rand()%300); query.bindValue(7,rand()%200000); query.bindValue(8,rand()%52); query.bindValue(9,rand()%100); //執行插入語句 success=query.exec(); if(!success) { QSqlError lastError=query.lastError(); qDebug()<<lastError.driverText()<<QString(QObject::tr("插入失敗")); } } qDebug()<<QObject::tr("插入 %1 條記錄，耗時：%2 ms").arg(records).arg(t.elapsed()); //排序 t.restart(); success=query.exec("select * from automobil order by id desc"); if(success) qDebug()<<QObject::tr("排序 %1 條記錄，耗時：%2 ms").arg(records).arg(t.elapsed()); else qDebug()<<QObject::tr("排序失敗！"); //更新記錄 t.restart(); for(int i=0;i<records;i++) { query.clear(); query.prepare(QString("update automobil set attribute=?,type=?," "kind=?,nation=?," "carnumber=?,elevaltor=?," "distance=?,oil=?," "temperature=? where id=%1").arg(i)); query.bindValue(0,"四輪"); query.bindValue(1,"轎車"); query.bindValue(2,"富康"); query.bindValue(3,rand()%100); query.bindValue(4,rand()%10000); query.bindValue(5,rand()%300); query.bindValue(6,rand()%200000); query.bindValue(7,rand()%52); query.bindValue(8,rand()%100); success=query.exec(); if(!success) { QSqlError lastError=query.lastError(); qDebug()<<lastError.driverText()<<QString(QObject::tr("更新失敗")); } } qDebug()<<QObject::tr("更新 %1 條記錄，耗時：%2 ms").arg(records).arg(t.elapsed()); //刪除 t.restart(); query.exec("delete from automobil where id=15"); qDebug()<<QObject::tr("刪除一條記錄，耗時：%1 ms").arg(t.elapsed()); return 0; //return a.exec();}

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