fieldinf1.cpp

MySql C++ library

#include <windows.h>
#include <iostream>
#include <iomanip>
#include <sqlplus.hh>

int main() {
  try { // its in one big try block

    Connection con(use_exceptions);
    con.connect("mysql_cpp_data");
    Query query = con.query();
    query << "select * from stock";
    Result res = query.store();
    
    cout << "Query: " << query.preview() << endl;
    cout << "Records Found: " << res.size() << endl << endl;

    cout << "Query Info:\n";
    cout.setf(ios::left);

    for (unsigned int i = 0; i < res.names().size(); i++) {
      cout << setw(2)  << i
	   << setw(15) << res.names(i).c_str()
	// this is the name of the field
	   << setw(15) << res.types(i).sql_name()
	// this is the SQL identifier name
	// Result::types(unsigned int) returns a mysql_type_info which in many
	// ways is like type_info except that it has additional sql type
	// information in it. (with one of the methods being sql_name())
	   << setw(20) << res.types(i).name()
	// this is the C++ identifier name which most closely resembles
	// the sql name (its is implementation defined and often not very readable)
	   << endl;
    }

    cout << endl;
    
    if (res.types(0) == typeid(string))
      cout << "Field 'item' is of an sql type which most closely resembles a\n"
	   << "the c++ string type\n";
    // this is demonstrating how a mysql_type_info can be compared with a c++
    // type_info.

    if (res.types(1) == typeid(longlong))
      cout << "Field 'num' is of an sql type which most closely resembles a\n"
	   << "the c++ long long int type\n";
    else if (res.types(1).base_type() == typeid(longlong))
      cout << "Field 'num' base type is of an sql type which most closely \n"
	   << "resembles a the c++ long long int type\n";
    // However you have to be careful as if it can be null the actual type is 
    // Null<TYPE> not TYPE.  So you should always use the base_type method
    // to get at the underlying type.  If the type is not null than this base
    // type would be the same as its type.
    
    return 0;
  } catch (BadQuery er) {
    cerr << "Error: " << er.error << endl;
    return -1;
  } catch (BadConversion er) { // handle bad conversions
    cerr << "Error: Tried to convert \"" << er.data << "\" to a \"" 
	 << er.type_name << "\"." << endl;
    return -1;
  }
}