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.

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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;
}

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