Qt TCP/IP C++ 数据库 历史数据操作部分

Qt TCP/IP C++ 数据库 历史数据操作部分
(1)对历史数据的查询操作。采样数据存储在数据库里，通过时间标签可以查询到之前存储的历史数据；

//查询
TimeTemp=ui->lineEdit->text().trimmed();
QSqlQuery *sqlQuery=new QSqlQuery(db);
QString command = QString("SELECT RtuName,TimeLabelStart,TimeLabelEnd,"
						"Data FROM RTU WHERE TimeLabelStart='%1' AND" 			
						"RtuName='%2';").arg(TimeTemp).arg(RTUNOTemp);
//判断查询是否成功
if(!sqlQuery->exec(command))
{
    ui->label_2->setText("data base check failed!");
}else	
{	//若查询成功，将数据调出查看
    while(sqlQuery->next())
    {
        NetData1= sqlQuery->value(3).toString();
        ReData1=NetData1.split(",");
        ui->label_2->setText("data base check successfully!");
        for (int i=0;i<100;i++)
            x[i]=ReData1.at(i).toDouble();
        LinePlotter->curve(x,100);
        //呈现在表中
    }
}

(2)对历史数据的删除操作。通过时间标签可以删除相应的历史数据；

//删除
LinePlotter->clearCurve(0);
//首先将图表中的曲线删除
TimeTemp=ui->lineEdit->text().trimmed();
QSqlQuery *sql=new QSqlQuery(db);
//SQL删除语言
QString command = QString("DELETE FROM RTU WHERE TimeLabelStart='%1' "
				"AND RtuName='%2';").arg(TimeTemp).arg(RTUNOTemp);
//判断数据是否删除成功
if(!sql->exec(command))
{
    //QMessageBox::information(this,"Title","delete failed!");
    ui->label_2->setText("delete failed!");
}else
{
    //QMessageBox::information(this,"Title","delete successfully!");
    ui->label_2->setText("delete successfully!");
}