sqlselect.C File Reference

Detailed Description

Query example to MySQL test database.

Example of query by using the test database made in MySQL, you need the database test installed in localhost, with user nobody without password.

 
#include <TSQLServer.h>
#include <TSQLResult.h>
#include <TSQLRow.h>
 
 
void sqlselect()
{
   TSQLServer *db = TSQLServer::Connect("mysql://localhost/test","nobody", "");
 
   printf("Server info: %s\n", db->ServerInfo());
 
   TSQLRow *row;
   TSQLResult *res;
 
   // list databases available on server
   printf("\nList all databases on server %s\n", db->GetHost());
   res = db->GetDataBases();
   while ((row = res->Next())) {
      printf("%s\n", row->GetField(0));
      delete row;
   }
   delete res;
 
   // list tables in database "test" (the permission tables)
   printf("\nList all tables in database \"test\" on server %s\n",
          db->GetHost());
   res = db->GetTables("test");
   while ((row = res->Next())) {
      printf("%s\n", row->GetField(0));
      delete row;
   }
   delete res;
 
   // list columns in table "runcatalog" in database "mysql"
   printf("\nList all columns in table \"runcatalog\" in database \"test\" on server %s\n",
          db->GetHost());
   res = db->GetColumns("test", "runcatalog");
   while ((row = res->Next())) {
      printf("%s\n", row->GetField(0));
      delete row;
   }
   delete res;
 
   // start timer
   TStopwatch timer;
   timer.Start();
 
   // query database and print results
   const char *sql = "select dataset,rawfilepath from test.runcatalog "
                     "WHERE tag&(1<<2) AND (run=490001 OR run=300122)";
   // const char *sql = "select count(*) from test.runcatalog "
   //                   "WHERE tag&(1<<2)";
 
   res = db->Query(sql);
 
   int nrows = res->GetRowCount();
   printf("\nGot %d rows in result\n", nrows);
 
   int nfields = res->GetFieldCount();
   for (int i = 0; i < nfields; i++)
      printf("%40s", res->GetFieldName(i));
   printf("\n");
   for (int i = 0; i < nfields*40; i++)
      printf("=");
   printf("\n");
 
   for (int i = 0; i < nrows; i++) {
      row = res->Next();
      for (int j = 0; j < nfields; j++) {
         printf("%40s", row->GetField(j));
      }
      printf("\n");
      delete row;
   }
 
   delete res;
   delete db;
 
   // stop timer and print results
   timer.Stop();
   Double_t rtime = timer.RealTime();
   Double_t ctime = timer.CpuTime();
 
   printf("\nRealTime=%f seconds, CpuTime=%f seconds\n", rtime, ctime);
}

Author

Sergey Linev, Juan Fernando Jaramillo Botero

Definition in file sqlselect.C.