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#ifndef MYGRATE_DBSTMT_H
#define MYGRATE_DBSTMT_H
#include <compileTimeFormatter.h>
#include <dbConn.h>
#include <dbRecordSet.h>
#include <memory>
#include <string_view>
#include <type_traits>
namespace MyGrate {
class DbConn;
enum class ParamMode { None, DollarNum, QMark };
template<AdHoc::support::basic_fixed_string S, ParamMode pm = ParamMode::None> class DbStmt {
public:
// This don't account for common table expressions, hopefully won't need those :)
static constexpr auto isSelect {S.v().starts_with("SELECT") || S.v().starts_with("SHOW")
|| S.v().find("RETURNING") != std::string_view::npos};
// These don't account for string literals, which we'd prefer to avoid anyway :)
static constexpr auto paramCount {[]() -> std::size_t {
switch (pm) {
case ParamMode::None:
return 0LU;
case ParamMode::DollarNum: {
const auto pn = [](const char * c, const char * const e) {
std::size_t n {0};
while (++c != e && *c >= '0' && *c <= '9') {
n = (n * 10) + (*c - '0');
}
return n;
};
return pn(std::max_element(S.v().begin(), S.v().end(),
[pn, e = S.v().end()](const char & a, const char & b) {
return (a == '$' ? pn(&a, e) : 0) < (b == '$' ? pn(&b, e) : 0);
}),
S.v().end());
}
case ParamMode::QMark:
return std::count_if(S.v().begin(), S.v().end(), [](char c) {
return c == '?';
});
}
}()};
using Return = std::conditional_t<isSelect, RecordSetPtr, std::size_t>;
template<typename... P>
static Return
execute(DbConn * c, P &&... p)
{
static_assert(sizeof...(P) == paramCount);
auto stmt {c->prepare(S, sizeof...(P))};
stmt->execute({std::forward<P...>(p)...});
if constexpr (isSelect) {
return stmt->recordSet();
}
else {
return stmt->rows();
}
}
};
}
#endif
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