spatialQuery.cpp

Shows how to use the database interface to do some spatial queries involving objects with points, lines and polygon geometries.

/************************************************************************************
TerraLib - a library for developing GIS applications.
Copyright © 2001-2004 INPE and Tecgraf/PUC-Rio.

This code is part of the TerraLib library.
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/* 
           This file shows an example of how to use the database interface to do some
           spatial queries involving objects with points, lines and polygon geometries.

           Authors: 
                      Karine Reis Ferreira  
                      Lubia Vinhas
*/

#include "../../src/terralib/drivers/MySQL/TeMySQL.h"
#include "../../src/terralib/drivers/shapelib/TeDriverSHPDBF.h"

int main()
{
           // Datatabase server parameters
           string host = "localhost";
           string dbname = "DB320RC1";
           string user = "root";
           string password = "vinhas";

           // Open a connection to the DB320RC1 MySQL database 
           TeDatabase* db = new TeMySQL();
           if (!db->connect(host, user, password, dbname))
           {
                      cout << "Error: " << db->errorMessage() << endl;
                      cout << endl << "Press Enter\n";
                      getchar();
                      return 1;
           }
           cout << "Connection successful to the database \"" << dbname << "\" on MySQL server \"" << host << "\" !\n";;

           // Check whether there is a layer of polygons called "Mapa_Distritos_SP".
           // In negative case, import it from the Mapa_Distritos_SP.shp file
           string layerName = "Mapa_Distritos_SP";

           TeDatum sad69 = TeDatumFactory::make("SAD69");
           TePolyconic* proj = new TePolyconic(sad69, -54*TeCDR);

           if (db->layerExist(layerName) == false)
           {
                      // Create a new layer in the database
                      TeLayer* layer = new TeLayer(layerName, db, proj);
                      string filename = "../data/Mapa_Distritos_SP.shp";     // Shapefile path
                      string tablename = "Mapa_Distritos_SP";     // Name of the attribute table

                      if (TeImportShape(layer, filename, tablename))
                                 cout << "The shapefile \"Mapa_Distritos_SP.shp\" was imported successfully into the TerraLib database!\n" << endl;
                      else
                                 cout << "Error: Fail to import the shapefile \"Mapa_Distritos_SP.shp\"!\n" << endl;
           }          

           // Check whether there is a layer of lines called "Mapa_Drenagem_SP".
           // In negative case, import it from the Mapa_Drenagem_SP.shp file
           layerName = "Mapa_Drenagem_SP";

           if (db->layerExist(layerName) == false)
           {
                      // Create a new layer in the database
                      TeLayer* layer = new TeLayer(layerName, db, proj);
                      string filename = "../data/Mapa_Drenagem_SP.shp";      // Shapefile path
                      string tablename = "Mapa_Drenagem_SP";      // Name of the attribute table

                      if (TeImportShape(layer, filename, tablename))
                                 cout << "The shapefile \"Mapa_Drenagem_SP.shp\" was imported successfully into the TerraLib database!\n" << endl;
                      else
                                 cout << "Error: Fail to import the shapefile \"Mapa_Drenagem_SP.shp\"!\n" << endl;
           }

           // Check whether there is a layer of points called "Mapa_Bairros_SP".
           // In negative case, import it from the Mapa_Bairros_SP.shp file
           layerName = "Mapa_Industrias_SP";

           if (db->layerExist(layerName) == false)
           {
                      // Create a new layer in the database
                      TeLayer* layer = new TeLayer(layerName, db, proj);
                      string filename = "../data/Mapa_Industrias_SP.shp";    // Shapefile path
                      string tablename = "Mapa_Industrias_SP";    // Name of the attribute table

                      if (TeImportShape(layer, filename, tablename))
                                 cout << "The shapefile \"Mapa_Industrias_SP.shp\" was imported successfully into the TerraLib database!\n" << endl;
                      else
                                 cout << "Error: Fail to import the shapefile \"Mapa_Industrias_SP.shp\"!\n" << endl;
           }

           // Retrieve from the database a layer of polygons, a layer of lines and a layer of points
    TeLayer* regions = new TeLayer("Mapa_Distritos_SP");                     // regions have polygons
    if (!db->loadLayer(regions))                
    {                                                                                               
        cout << "Fail to load layer \"Mapa_Distritos_SP\": " << db->errorMessage() << endl;
                      cout << endl << "Press Enter\n";
                      getchar();
                      return 1;
    }

    TeLayer* rivers = new TeLayer("Mapa_Drenagem_SP"); // rivers have lines
    if (!db->loadLayer(rivers))                
    {                                                                                               
        cout << "Fail to load layer \"Mapa_Drenagem_SP\": " << db->errorMessage() << endl;
                      cout << endl << "Press Enter\n";
                      getchar();
                      return 1;
    }

           TeLayer* industries = new TeLayer("Mapa_Industrias_SP");          // districts have points
    if (!db->loadLayer(industries))                
    {                                                                                               
        cout << "Fail to load layer \"Mapa_Industrias_SP\": " << db->errorMessage() << endl;
                      cout << endl << "Press Enter\n";
                      getchar();
                      return 1;
    }

           //get precision from projection
           TePrecision::instance().setPrecision(TeGetPrecision(proj));       
           
           vector<string> objsOut;          // holds the identification of the resulting objects
           
           vector<string> objsIn;  // objects to be queried                  
           objsIn.push_back("48");

           // Retrieve the regions that are adjacent or touch the district 48
           bool res = db->spatialRelation(regions->tableName(TePOLYGONS), TePOLYGONS, objsIn,
                                            objsOut, TeTOUCHES);
           if (res)
           {
                      cout << "Regions that touch the region \"48\": \n";
                      unsigned int i;
                      for (i=0; i<objsOut.size(); i++)
                                 cout << "Regions: " << objsOut[i] << endl;

           }

           // Retrieve the rivers that cross the district 48
           res = db->spatialRelation(regions->tableName(TePOLYGONS), TePOLYGONS, objsIn,
                                                  rivers->tableName(TeLINES), TeLINES, objsOut, TeCROSSES);
           if (res)
           {
                      cout << "\nRivers that cross the region \"48\": \n";
                      unsigned int i;
                      for (i=0; i<objsOut.size(); i++)
                                 cout << "River: " << objsOut[i] << endl;
           }

           // Retrieve the industries that are within the district 48
           res = db->spatialRelation(regions->tableName(TePOLYGONS), TePOLYGONS, objsIn,
                                            industries->tableName(TePOINTS), TePOINTS, objsOut, TeWITHIN);
           if (res)
           {
                      cout << "\nIndustries that are within the region \"48\": \n";
                      unsigned int i;
                      for (i=0; i<objsOut.size(); i++)
                                 cout << "Industry: " << objsOut[i] << endl;

           }

           db->close();
           cout << endl << "Press Enter\n";
           cout.flush();
           getchar();
           return 0;
}