Получение данных
Следующий пример показывает довольно интересное понятие, известное как Specialized SQL Structures (SSQLS). Имя файла для этого кода: custom1.cc. #include <iostream> #include <iomanip> #include <vector> #include <sqlplus.hh> #include <custom.hh>
sql_create_5 (stock, 1, 5, string, item, int, num, double, weight, double, price, Date, sdate)
// this is calling a very complex macro which will create a custom // struct "stock" which has the variables: // string item // int num // ... // Date sdate // defined as well methods to help populate the class from a mysql row // among other things that I'll get too in a latter example int main () { try { Connection con (use_exceptions); con.connect ("mysql_cpp_data"); Query query = con.query (); query << "select * from stock"; vector < stock > res; query.storein (res); // this is storing the results into a vector of the custom struct // "stock" which was created my the macro above. cout.setf (ios::left); cout << setw (17) << "Item" << setw (4) << "Num" << setw (7) << "Weight" << setw (7) << "Price" << "Date" << endl << endl; cout.precision(3); vector <stock>::iterator i; for (i = res.begin (); i != res.end (); i++) { cout << setw (17) << i->item.c_str () << setw (4) << i->num << setw (7) << i->weight << setw (7) << i->price << i->sdate << endl; } return 0; } catch (BadQuery er) { // handle any connection // or query errors that may come up cerr << "Error: " << er.error << endl; return -1; } catch (BadConversion er) { // we still need to cache bad conversions incase something goes // wrong when the data is converted into stock cerr << "Error: Tried to convert \"" << er.data << "\" to a \"" << er.type_name << "\"." << endl; return -1; } }
Как Вы можете видеть, SSQLS очень мощная штука.
