16 #include "pqxx/compiler-public.hxx" 17 #include "pqxx/internal/compiler-internal-pre.hxx" 21 #include "pqxx/array.hxx" 22 #include "pqxx/composite.hxx" 23 #include "pqxx/result.hxx" 24 #include "pqxx/strconv.hxx" 25 #include "pqxx/types.hxx" 43 PQXX_DEPRECATED(
"Do not construct fields yourself. Get them from the row.")
47 PQXX_DEPRECATED("Do not construct fields yourself. Get them from the
row.")
71 [[nodiscard]] PQXX_PURE
bool operator==(
field const &) const;
76 [[nodiscard]] PQXX_PURE
bool operator!=(
field const &rhs)
const 78 return not operator==(rhs);
86 [[nodiscard]] PQXX_PURE
char const *name()
const;
90 [[nodiscard]] oid PQXX_PURE type()
const;
93 [[nodiscard]] PQXX_PURE oid table()
const;
106 [[nodiscard]] PQXX_PURE std::string_view view()
const 109 return std::string_view(c_str(), size());
122 [[nodiscard]] PQXX_PURE
char const *c_str()
const;
125 [[nodiscard]] PQXX_PURE
bool is_null()
const noexcept;
128 [[nodiscard]] PQXX_PURE
size_type size()
const noexcept;
135 auto to(T &obj)
const ->
typename std::enable_if_t<
136 (not std::is_pointer<T>::value or std::is_same<T, char const *>::value),
145 auto const bytes{c_str()};
171 template<
typename T>
bool operator>>(T &obj)
const {
return to(obj); }
185 auto to(T &obj, T
const &default_value)
const ->
typename std::enable_if_t<
186 (not std::is_pointer<T>::value or std::is_same<T, char const *>::value),
193 obj = from_string<T>(this->view());
201 template<
typename T> T
as(T
const &default_value)
const 204 return default_value;
206 return from_string<T>(this->view());
215 template<
typename T> T
as()
const 230 return from_string<T>(this->view());
238 template<
typename T,
template<
typename>
class O = std::optional>
239 constexpr O<T>
get()
const 275 template<>
inline bool field::to<std::string>(std::string &obj)
const 279 obj = std::string{view()};
285 inline bool field::to<std::string>(
286 std::string &obj, std::string
const &default_value)
const 292 obj = std::string{view()};
303 template<>
inline bool field::to<char const *>(
char const *&obj)
const 312 template<>
inline bool field::to<std::string_view>(std::string_view &obj)
const 322 inline bool field::to<std::string_view>(
323 std::string_view &obj, std::string_view
const &default_value)
const 334 template<>
inline std::string_view field::as<std::string_view>()
const 343 inline std::string_view
344 field::as<std::string_view>(std::string_view
const &default_value)
const 346 return is_null() ? default_value : view();
350 template<>
inline bool field::to<zview>(
zview &obj)
const 354 obj =
zview{c_str(), size()};
360 inline bool field::to<zview>(
zview &obj,
zview const &default_value)
const 366 obj =
zview{c_str(), size()};
371 template<>
inline zview field::as<zview>()
const 375 return zview{c_str(), size()};
379 template<>
inline zview field::as<zview>(
zview const &default_value)
const 381 return is_null() ? default_value :
zview{c_str(), size()};
385 template<
typename CHAR =
char,
typename TRAITS = std::
char_traits<CHAR>>
400 virtual int sync()
override {
return traits_type::eof(); }
404 return traits_type::eof();
408 return traits_type::eof();
414 field const &m_field;
418 auto g{
static_cast<char_type *
>(
const_cast<char *
>(m_field.
c_str()))};
419 this->setg(g, g, g + std::size(m_field));
420 return int_type(std::size(m_field));
434 template<
typename CHAR =
char,
typename TRAITS = std::
char_traits<CHAR>>
437 using super = std::basic_istream<CHAR, TRAITS>;
478 template<
typename CHAR>
479 inline std::basic_ostream<CHAR> &
480 operator<<(std::basic_ostream<CHAR> &s,
field const &value)
482 s.write(value.c_str(), std::streamsize(std::size(value)));
502 return from_string<T>(value.
view());
515 inline std::nullptr_t from_string<std::nullptr_t>(
field const &value)
517 if (not value.is_null())
519 "Extracting non-null field into nullptr_t variable."};
525 template<> PQXX_LIBEXPORT std::string
to_string(
field const &value);
528 #include "pqxx/internal/compiler-internal-post.hxx" typename traits_type::off_type off_type
Definition: field.hxx:444
virtual pos_type seekpos(pos_type, openmode) override
Definition: field.hxx:406
Reference to one row in a result.
Definition: row.hxx:45
Value conversion failed, e.g. when converting "Hello" to int.
Definition: except.hxx:178
PQXX_PURE std::string_view view() const
Read as string_view, or an empty one if null.
Definition: field.hxx:107
row_size_type m_col
Definition: field.hxx:267
typename traits_type::int_type int_type
Definition: field.hxx:442
virtual int sync() override
Definition: field.hxx:400
void parse_composite(pqxx::internal::encoding_group enc, std::string_view text, T &...fields)
Parse a string representation of a value of a composite type.
Definition: composite.hxx:33
The home of all libpqxx classes, functions, templates, etc.
Definition: array.hxx:25
bool is_null(TYPE const &value) noexcept
Is value null?
Definition: strconv.hxx:353
field_streambuf(field const &f)
Definition: field.hxx:397
typename traits_type::pos_type pos_type
Definition: field.hxx:392
PQXX_PURE bool is_null() const noexcept
Is this field's value null?
Definition: field.cxx:66
Definition: field.hxx:386
row_size_type col() const noexcept
Definition: field.hxx:261
std::string to_string(field const &value)
Convert a field to a string.
Definition: result.cxx:503
TRAITS traits_type
Definition: field.hxx:390
TRAITS traits_type
Definition: field.hxx:441
typename traits_type::off_type off_type
Definition: field.hxx:393
std::size_t field_size_type
Number of bytes in a field of database data.
Definition: types.hxx:30
array_parser as_array() const
Parse the field as an SQL array.
Definition: field.hxx:251
void throw_null_conversion(std::string const &type)
Definition: strconv.cxx:242
result const & home() const noexcept
Definition: field.hxx:259
bool composite_to(T &...fields) const
Read field as a composite value, write its components into fields.
Definition: field.hxx:157
std::ios::seekdir seekdir
Definition: field.hxx:395
Low-level array parser.
Definition: array.hxx:46
virtual int_type underflow() override
Definition: field.hxx:411
field_size_type size_type
Definition: field.hxx:36
T from_string(field const &value)
Convert a field's value to type T.
Definition: field.hxx:491
typename traits_type::pos_type pos_type
Definition: field.hxx:443
PQXX_PURE row_size_type num() const
Return row number. The first row is row 0, the second is row 1, etc.
Definition: field.hxx:96
result_size_type size_type
Definition: result.hxx:73
Reference to a field in a result set.
Definition: field.hxx:33
CHAR char_type
Definition: field.hxx:389
Traits describing a type's "null value," if any.
Definition: strconv.hxx:86
Input stream that gets its data from a result field.
Definition: field.hxx:435
Result set containing data returned by a query or command.
Definition: result.hxx:70
result::size_type idx() const noexcept
Definition: field.hxx:260
auto to(T &obj) const -> typename std::enable_if_t<(not std::is_pointer< T >::value or std::is_same< T, char const *>::value), bool >
Read value into obj; or if null, leave obj untouched and return false.
Definition: field.hxx:135
basic_fieldstream(field const &f)
Definition: field.hxx:446
static TYPE null()
Return a null value.
PQXX_PURE char const * c_str() const
Read as plain C string.
Definition: field.cxx:60
typename traits_type::int_type int_type
Definition: field.hxx:391
auto to(T &obj, T const &default_value) const -> typename std::enable_if_t<(not std::is_pointer< T >::value or std::is_same< T, char const *>::value), bool >
Read value into obj; or if null, use default value and return false.
Definition: field.hxx:185
std::ios::openmode openmode
Definition: field.hxx:394
Marker-type wrapper: zero-terminated std::string_view.
Definition: zview.hxx:37
int row_size_type
Number of fields in a row of database data.
Definition: types.hxx:24
virtual pos_type seekoff(off_type, seekdir, openmode) override
Definition: field.hxx:402
T as(T const &default_value) const
Return value as object of given type, or default value if null.
Definition: field.hxx:201
CHAR char_type
Definition: field.hxx:440
virtual int_type overflow(int_type) override
Definition: field.hxx:410
T as() const
Return value as object of given type, or throw exception if null.
Definition: field.hxx:215
bool operator>>(T &obj) const
Read value into obj; or leave obj untouched and return false if null.
Definition: field.hxx:171