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Revision 6e4119a4

Added by David Sorber over 9 years ago

I finally got back to working on this POC, and I was able to get it mostly working. The only issue right now is that the template magic is attempting to create code for which the types don't match and don't cast decay nicely. That is if you try to assign a std::string to a tuple. Hopefully I can fix this with a bit of massaging.

View differences:

software/sqlite_poc/main.cc
#include <iomanip>
#include <iostream>
#include <tuple>
#include "DBManager.h"
// helper function to print a tuple of any size
template<class Tuple, std::size_t N>
struct TuplePrinter {
static void print(const Tuple& t)
{
TuplePrinter<Tuple, N-1>::print(t);
std::cout << ", " << std::get<N-1>(t);
}
};
template<class Tuple>
struct TuplePrinter<Tuple, 1> {
static void print(const Tuple& t)
{
std::cout << std::get<0>(t);
}
};
template<class... Args>
void print(const std::tuple<Args...>& t)
{
std::cout << "(";
TuplePrinter<decltype(t), sizeof...(Args)>::print(t);
std::cout << ")\n";
}
int main(int argc, char** argv)
{
std::cout << "SQLite Proof of Concept Exerciser" << std::endl;
// Make a DBManager instance which will connect to our test DB automagically
DBManager db_mgr("database.db");
db_mgr.test();
//~ std::tuple<std::string, int, double> foo{"hello", 120, 3.14};
//~ db_mgr.func(foo);
//~ visit_at(foo, 1, 18);
std::string query("SELECT Number FROM sample;");
int rc(0);
auto results = db_mgr.execute_query<std::tuple<int64_t>>(query, rc);
// Make a query
std::string query("SELECT Number, Float FROM sample;");
// Execute the query making sure the template params match up with the
// query params
int rc = 0;
auto results = db_mgr.execute_query<int64_t, double>(query, rc);
std::cout << "Return code: " << rc << std::endl;
// If we returned successfully, print out the result rows
if (! rc)
{
uint32_t row_index = 0;
for (auto row : *results)
{
std::cout << "Row: " << std::setw(4) << row_index << " - ";
print(*row);
++row_index;
}
}
return 0;
}

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