dtl

// Example Code Using LoggingHandler on a DBView



// test of failed SelValidate() when reading data

void TestBadSelValidate()

{

 	vector<Example> results;



	// construct view

	// DBView<Example> is actually DBView<Example, 

	// DefaultParamObj<Example> > thanks to the default 

	// argument to the DBView template



	// use our bad BCA which references a nonexistent column name in DB_EXAMPLE

	DBView<Example>

		view("DB_EXAMPLE", BCAExampleObj(),

		"WHERE INT_VALUE BETWEEN (?) AND (?) AND "

		"STRING_VALUE = (?) OR EXAMPLE_DATE < (?) ORDER BY EXAMPLE_LONG",

		BPAExampleObj(), BadSelValidate());



	view.set_io_handler(LoggingHandler<Example>());



	// loop through query results and add them to our vector

	// in this loop, read_it.GetLastCount() records read from DB



	DBView<Example>::select_iterator read_it = view.begin();



	// set parameter values for the WHERE clause in our SQL query

	read_it.Params().lowIntValue = 2;

	read_it.Params().highIntValue = 8;

	read_it.Params().strValue = "Example";

	

	TIMESTAMP_STRUCT paramDate = {2000, 1, 1, 0, 0, 0, 0};

	read_it.Params().dateValue = paramDate;



	for ( ; read_it != view.end(); read_it++)

	{

		try

		{

		  // note that the read_iterator::GetLastCount()  is incremented in operator++()

		  // remember that the record is fetched and thus the count incremented

		  // before operator*() is applied to the read_iterator



		  cout << "Reading element #" << read_it.GetLastCount() << endl;

		  

		  cout << "read_it->exampleInt = " << read_it->exampleInt << endl;

		  cout << "read_it->exampleStr = " << read_it->exampleStr << endl;

		  

		  results.push_back(*read_it);

		}

		catch (RootException &ex)

		{

		  cout << "Caught Exception!!!!" << endl;

		  cout << ex.what() << endl;

		}

	}



	LoggingHandler<Example> handler = 

		read_it.get_io_handler((LoggingHandler<Example> *) NULL);



	typedef LoggingHandler<Example>::LoggedTriple LoggedTriple;



	vector<LoggedTriple> errors = handler.GetLog();



	for (vector<LoggedTriple>::iterator log_it = errors.begin(); log_it != errors.end();

			log_it++)

	{

		LoggedTriple error = *log_it;



		cout << "Error msg = " << error.errmsg << endl;

		cout << "Example = " << error.dataObj << endl;

	}



}

Copyright © 2002, Michael Gradman and Corwin Joy.

Permission to use, copy, modify, distribute and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appears in all copies and that both that copyright notice and this permission notice appear in supporting documentation. Corwin Joy and Michael Gradman make no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.

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