這里主要是個事例，并不涉及業(yè)務邏輯處理。在此記錄下。

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程序運行截圖如下：

這里有下面這個類BigDataTest對數(shù)據(jù)進行的類。

MySQLInstance采用單例雙重鎖模式對數(shù)據(jù)庫進行操作。

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源碼如下：

BigDataTest.h

#ifndef CONCURRENT_H #define CONCURRENT_H#include <QObject> #include <QList>class BigDataTest : public QObject {Q_OBJECT public:BigDataTest(QObject *parent = 0);void run();protected:bool connectMySQL();friend QString sqlResult(const QString &cmd);private:QList<QString> m_str; };#endif // CONCURRENT_H

MySQLInstance.h

#ifndef MYSQLINSTANCE_H #define MYSQLINSTANCE_H#include <QSqlDatabase>class MySQLInstance { public:static MySQLInstance *getInstance();QString execSql(const QString &cmd);protected:MySQLInstance();void connectMySQL();private:static MySQLInstance *m_instance;QSqlDatabase m_db; };#endif // MYSQLINSTANCE_H

BigDataTest.cpp

#include "BigDataTest.h" #include "MySQLInstance.h" #include <QDebug> #include <QtConcurrent> #include <QSqlQuery>BigDataTest::BigDataTest(QObject *parent) : QObject(parent) {m_str << "SELECT 1 + 1" << "SELECT 100 * 100 * 100 / 10" << "SELECT 100 + 99" << "SELECT 1 + 1"<< "SELECT 1 + 1 + 500" << "SELECT 1 + 1 + 1000" << "SELECT 1999 - 199" << "SELECT 1999 + 10"<< "SELECT 1 + 1 + 8888" << "SELECT 1 + 1 + 788"; }QString sqlResult(const QString &cmd) {qDebug() << "處理SQL語句進程 : " << QThread::currentThread();MySQLInstance *instance = MySQLInstance::getInstance();return instance->execSql(cmd); }void BigDataTest::run() {QList<QString> retList = QtConcurrent::blockingMapped(m_str, sqlResult);qDebug() << "返回結果";qDebug() << retList; }

main.cpp

#include <QCoreApplication> #include "BigDataTest.h"int main(int argc, char *argv[]) {QCoreApplication a(argc, argv);BigDataTest bigDataTest;bigDataTest.run();return a.exec(); }

MySQLInstance.cpp

#include "MySQLInstance.h" #include <QSqlQuery> #include <QSqlError> #include <QDebug> #include <QMutex> #include <QVariant>MySQLInstance *MySQLInstance::m_instance = nullptr; QMutex mt;MySQLInstance *MySQLInstance::getInstance() {if(m_instance == nullptr){mt.lock();if(m_instance == nullptr){m_instance = new MySQLInstance();mt.unlock();return m_instance;}mt.unlock();}return m_instance; }QString MySQLInstance::execSql(const QString &cmd) {if(m_instance == nullptr){Q_ASSERT(!"m_instance == nullptr");}//簡單點，返回值只有一個mt.lock();QSqlQuery query(m_db);if(!query.exec(cmd)){mt.unlock();qDebug() << "error:" << query.lastError().text();return "error";}mt.unlock();QString ret = "none";while(query.next()){ret = query.value(0).toString();}return ret; }MySQLInstance::MySQLInstance() {connectMySQL(); }void MySQLInstance::connectMySQL() {m_db = QSqlDatabase::addDatabase("QMYSQL");m_db.setHostName("127.0.0.1");m_db.setPort(3306);m_db.setDatabaseName("mysql");m_db.setUserName("root");m_db.setPassword("root");m_db.open(); }

程序打包下載地址：

https://github.com/fengfanchen/Qt/tree/master/DealWithBigData

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