SQLiteVersionsOfRoot.C File Reference

Detailed Description

This tutorial demonstrates how TSQLServer can be used to create a connection with a SQlite3 database. It accesses the Sqlite data base. Download from https://root.cern/download/root_download_stats.sqlite Then a TH1F histogram is created and filled using a expression which receives the recorded values in the “version” column of the sqlite3 database. The histogram shows the usage of the ROOT development version. This product includes GeoLite2 data created by MaxMind, available from http://www.maxmind.com.

 
#include <TSQLiteServer.h>
#include <TSQLiteResult.h>
#include <TSQLRow.h>
#include <TString.h>
 
void SQLiteVersionsOfRoot(){
 
   TSQLServer *db = TSQLServer::Connect("sqlite://root_download_stats.sqlite", "", "");
 
   const char *rootSourceVersion = "SELECT Version FROM accesslog;";
 
   TSQLResult *rootSourceVersionRes = db->Query(rootSourceVersion);
 
   TH1F *hVersionOfRoot= new TH1F("hVersionOfRoot", "Development Versions of ROOT", 7, 0, -1);
 
   while (TSQLRow *row = rootSourceVersionRes->Next()) {
      TString rowVersion(row->GetField(0));
      TString shortVersion(rowVersion(0,4));
      hVersionOfRoot->Fill(shortVersion,1);
      delete row;
   }
 
   TCanvas *VersionOfRootHistogram = new TCanvas();
 
   hVersionOfRoot->GetXaxis()->LabelsOption("a");
   hVersionOfRoot->LabelsDeflate("X");
   hVersionOfRoot->Draw();
}

Author

Alexandra-Maria Dobrescu 08/2018

Definition in file SQLiteVersionsOfRoot.C.