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querierFromLayer.cpp

Shows how to use a querier from layer

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

    This code is part of the TerraLib library.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    You should have received a copy of the GNU Lesser General Public
    License along with this library.

    The authors reassure the license terms regarding the warranties.
    They specifically disclaim any warranties, including, but not limited to,
    the implied warranties of merchantability and fitness for a particular purpose.
    The library provided hereunder is on an "as is" basis, and the authors have no
    obligation to provide maintenance, support, updates, enhancements, or modifications.
    In no event shall INPE and Tecgraf / PUC-Rio be held liable to any party for direct,
    indirect, special, incidental, or consequential damages arising out of the use
    of this library and its documentation.
    *************************************************************************************/
    /*
       This example shows how to use a querier from layer.

       Author: Karine Reis
    */

    #include "../../src/terralib/drivers/MySQL/TeMySQL.h"
    #include "../../src/terralib/kernel/TeQuerier.h"
    #include "../../src/terralib/kernel/TeQuerierParams.h"

    #include <time.h>
    #include <iostream>

    using std::cout;

    int
    main()
    {

               // Datatabase server parameters
         string host = "localhost";
         string dbname = "DB320RC1";
         string user = "root";
         string pass = "vinhas";

                // Connects to database
         TeDatabase* db_ = new TeMySQL();
         if (!db_->connect(host,user,pass,dbname))
         {
             cout << "Error: " << db_->errorMessage() << endl;
                           getchar();
             return 1;
         }

               // Load the layer
               TeLayer* ocorrencias = new TeLayer("Cadastro_Escolas");
               if (!db_->loadLayer(ocorrencias))
        {
            cout << "Error: " << db_->errorMessage() << endl;
                          db_->close();
                          getchar();
            return 1;
        }

               bool loadAllAttributes = true;
               bool loadGeometries = false;

               // Set querier parameters - load all attributes and no geometries of the layer "ocorrencias"
               TeQuerierParams querierParams(loadGeometries, loadAllAttributes);
               querierParams.setParams(ocorrencias);

               TeQuerier  querier(querierParams);

               // Load instances from layer based in the querier parameters
               if(!querier.loadInstances())
               {
                          cout << "Error loading instances... " << endl;
                          db_->close();
            return 1;
               }

               // Return a list of the loaded attributes
               TeAttributeList attrList = querier.getAttrList();

               cout << " Loaded Attributes  -------------------  " << endl;

               // Plot the attribute names
               for(unsigned int i=0; i<attrList.size(); ++i)
                          cout << attrList[i].rep_.name_ << endl;

               cout << endl;

               // Traverse all the instances
               TeSTInstance sti;
               while(querier.fetchInstance(sti))
               {
                          cout << " Object: " << sti.objectId() << " --------------------------- " << endl << endl;

                          // Plot each attribute, its name and value
                          TePropertyVector vec = sti.getPropertyVector();
                          for(unsigned int i=0; i<vec.size(); ++i)
                          {
                                     string  attrName = vec[i].attr_.rep_.name_;
                                     string  attrValue = vec[i].value_;
                                     cout << attrName  << " : " << attrValue << endl;

                          }
               }

               cout << endl << " Press enter! " << endl;
               getchar();
               db_->close ();
               return 0;
    }

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