mirror of
https://github.com/boostorg/mysql.git
synced 2026-02-14 12:52:17 +00:00
90 lines
3.1 KiB
C++
90 lines
3.1 KiB
C++
//
|
|
// Copyright (c) 2019-2022 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
#ifndef BOOST_MYSQL_STATEMENT_BASE_HPP
|
|
#define BOOST_MYSQL_STATEMENT_BASE_HPP
|
|
|
|
|
|
#include <boost/mysql/detail/protocol/prepared_statement_messages.hpp>
|
|
#include <boost/mysql/field_view.hpp>
|
|
#include <array>
|
|
#include <cstdint>
|
|
|
|
namespace boost {
|
|
namespace mysql {
|
|
|
|
/// Convenience constant to use when executing a statement without parameters.
|
|
constexpr std::array<field_view, 0> no_statement_params {};
|
|
|
|
/**
|
|
* \brief Represents a prepared statement. See [link mysql.prepared_statements] for more info.
|
|
* \details This class is a handle to a server-side prepared statement.
|
|
*
|
|
* The main use of a prepared statement is executing it
|
|
* using [refmem statement_base execute], which yields a [reflink resultset_base].
|
|
*
|
|
* Prepared statements are default-constructible and movable, but not copyable.
|
|
* [refmem statement_base valid] returns `false` for default-constructed
|
|
* and moved-from prepared statements. Calling any member function on an invalid
|
|
* prepared statements, other than assignment, results in undefined behavior.
|
|
*
|
|
* Prepared statements are managed by the server in a per-connection basis:
|
|
* once created, a prepared statement may be used as long as the parent
|
|
* [reflink connection] object (i.e. the connection that originated the resultset_base)
|
|
* is alive and open. Calling any function on a statement_base
|
|
* whose parent connection has been closed or destroyed results
|
|
* in undefined behavior.
|
|
*/
|
|
class statement_base
|
|
{
|
|
public:
|
|
/**
|
|
* \brief Default constructor.
|
|
* \details Default constructed statements have [refmem statement_base valid] return `false`.
|
|
*/
|
|
statement_base() = default;
|
|
|
|
#ifndef BOOST_MYSQL_DOXYGEN
|
|
// Private. Do not use. TODO: hide this
|
|
void reset(
|
|
void* channel,
|
|
const detail::com_stmt_prepare_ok_packet& msg
|
|
) noexcept
|
|
{
|
|
channel_ = channel;
|
|
stmt_msg_ = msg;
|
|
}
|
|
|
|
void reset() noexcept { channel_ = nullptr; }
|
|
#endif
|
|
|
|
/**
|
|
* \brief Returns `true` if the statement is not a default-constructed object.
|
|
* \details Calling any function other than assignment on an statement for which
|
|
* this function returns `false` results in undefined behavior.
|
|
*/
|
|
bool valid() const noexcept { return channel_ != nullptr; }
|
|
|
|
/// Returns a server-side identifier for the statement (unique in a per-connection basis).
|
|
std::uint32_t id() const noexcept { assert(valid()); return stmt_msg_.statement_id; }
|
|
|
|
/// Returns the number of parameters that should be provided when executing the statement.
|
|
unsigned num_params() const noexcept { assert(valid()); return stmt_msg_.num_params; }
|
|
|
|
protected:
|
|
void* channel_ptr() noexcept { return channel_; }
|
|
void swap(statement_base& other) noexcept { std::swap(*this, other); }
|
|
private:
|
|
void* channel_ {nullptr};
|
|
detail::com_stmt_prepare_ok_packet stmt_msg_;
|
|
};
|
|
|
|
} // mysql
|
|
} // boost
|
|
|
|
#endif /* INCLUDE_BOOST_MYSQL_PREPARED_STATEMENT_HPP_ */
|