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00014 #ifndef PQXX_RESULT_H
00015 #define PQXX_RESULT_H
00016
00017 #include <stdexcept>
00018
00019 #include "pqxx/util.h"
00020
00021
00022
00023
00024
00025
00026
00027 namespace pqxx
00028 {
00029
00031
00038 class PQXX_LIBEXPORT Result
00039 {
00040 public:
00041 Result() : m_Result(0), m_Refcount(0) {}
00042 Result(const Result &rhs) :
00043 m_Result(0), m_Refcount(0) { MakeRef(rhs); }
00044 ~Result() { LoseRef(); }
00045
00046 Result &operator=(const Result &);
00047
00048 typedef Result_size_type size_type;
00049 class Field;
00050
00051
00052
00054
00062 class PQXX_LIBEXPORT Tuple
00063 {
00064 public:
00065 typedef Tuple_size_type size_type;
00066 Tuple(const Result *r, Result::size_type i) : m_Home(r), m_Index(i) {}
00067 ~Tuple() {}
00068
00069 inline Field operator[](size_type) const;
00070 Field operator[](const char[]) const;
00071 Field operator[](const PGSTD::string &s) const
00072 { return operator[](s.c_str()); }
00073 Field at(size_type) const;
00074 Field at(const char[]) const;
00075 Field at(const PGSTD::string &s) const { return at(s.c_str()); }
00076
00077 inline size_type size() const;
00078
00079 Result::size_type Row() const { return m_Index; }
00080
00081 size_type ColumnNumber(const PGSTD::string &ColName) const
00082 { return m_Home->ColumnNumber(ColName); }
00083
00084 size_type ColumnNumber(const char ColName[]) const
00085 { return m_Home->ColumnNumber(ColName); }
00086
00087 protected:
00088 const Result *m_Home;
00089 Result::size_type m_Index;
00090
00091
00092 Tuple();
00093 };
00094
00095
00097
00100 class PQXX_LIBEXPORT Field : private Tuple
00101 {
00102 public:
00103 typedef size_t size_type;
00104
00106
00110 Field(const Tuple &R, Tuple::size_type C) : Tuple(R), m_Col(C) {}
00111
00113
00118 const char *c_str() const {return m_Home->GetValue(m_Index,m_Col);}
00119
00121 inline const char *Name() const;
00122
00124 template<typename T> bool to(T &Obj) const
00125 {
00126 if (is_null())
00127 return false;
00128
00129 try
00130 {
00131 FromString(c_str(), Obj);
00132 }
00133 catch (const PGSTD::exception &e)
00134 {
00135 throw PGSTD::runtime_error("Error reading field " +
00136 PGSTD::string(Name()) +
00137 ": " +
00138 e.what());
00139 }
00140 return true;
00141 }
00142
00143
00144 #ifdef NO_PARTIAL_CLASS_TEMPLATE_SPECIALISATION
00145
00146 template<> bool to<PGSTD::string>(PGSTD::string &Obj) const;
00147
00149
00152 template<> bool to<const char *>(const char *&Obj) const;
00153 #endif
00154
00155
00157 template<typename T> bool to(T &Obj, const T &Default) const
00158 {
00159 const bool NotNull = to(Obj);
00160 if (!NotNull)
00161 Obj = Default;
00162 return NotNull;
00163 }
00164
00165 bool is_null() const { return m_Home->GetIsNull(m_Index,m_Col); }
00166
00167 size_type size() const { return m_Home->GetLength(m_Index,m_Col); }
00168
00169 private:
00170
00171 Tuple::size_type m_Col;
00172 };
00173
00174
00176
00180 class PQXX_LIBEXPORT const_iterator :
00181 public PGSTD::iterator<PGSTD::random_access_iterator_tag,
00182 const Tuple,
00183 Result::size_type>,
00184 public Tuple
00185 {
00186 public:
00187 const_iterator() : Tuple(0,0) {}
00188
00195 pointer operator->() const { return this; }
00196 reference operator*() const { return *operator->(); }
00197
00198 const_iterator operator++(int);
00199 const_iterator &operator++() { ++m_Index; return *this; }
00200 const_iterator operator--(int);
00201 const_iterator &operator--() { --m_Index; return *this; }
00202
00203 const_iterator &operator+=(difference_type i)
00204 { m_Index+=i; return *this; }
00205 const_iterator &operator-=(difference_type i)
00206 { m_Index-=i; return *this; }
00207
00208 bool operator==(const const_iterator &i) const
00209 {return m_Index==i.m_Index;}
00210 bool operator!=(const const_iterator &i) const
00211 {return m_Index!=i.m_Index;}
00212 bool operator<(const const_iterator &i) const
00213 {return m_Index<i.m_Index;}
00214 bool operator<=(const const_iterator &i) const
00215 {return m_Index<=i.m_Index;}
00216 bool operator>(const const_iterator &i) const
00217 {return m_Index>i.m_Index;}
00218 bool operator>=(const const_iterator &i) const
00219 {return m_Index>=i.m_Index;}
00220
00221 inline const_iterator operator+(difference_type o) const;
00222
00223 friend const_iterator operator+(difference_type o,
00224 const_iterator i);
00225
00226 inline const_iterator operator-(difference_type o) const;
00227
00228 inline difference_type operator-(const_iterator i) const;
00229
00230 Result::size_type num() const { return Row(); }
00231
00232 private:
00233 friend class Result;
00234 const_iterator(const Result *r, Result::size_type i) : Tuple(r, i) {}
00235 };
00236
00237 const_iterator begin() const { return const_iterator(this, 0); }
00238 inline const_iterator end() const;
00239
00240
00241 size_type size() const { return m_Result ? PQntuples(m_Result) : 0; }
00242 bool empty() const { return !m_Result || !PQntuples(m_Result); }
00243 size_type capacity() const { return size(); }
00244
00245 const Tuple operator[](size_type i) const { return Tuple(this, i); }
00246 const Tuple at(size_type) const;
00247
00248 void clear() { LoseRef(); }
00249
00250 Tuple::size_type Columns() const { return PQnfields(m_Result); }
00251
00253 Tuple::size_type ColumnNumber(const char Name[]) const
00254 {return PQfnumber(m_Result,Name);}
00256 Tuple::size_type ColumnNumber(const std::string &Name) const
00257 {return ColumnNumber(Name.c_str());}
00258 const char *ColumnName(Tuple::size_type Number) const
00259 {return PQfname(m_Result,Number);}
00260
00262
00263 Oid InsertedOid() const { return PQoidValue(m_Result); }
00264
00266
00267 size_type AffectedRows() const;
00268
00269 private:
00270 PGresult *m_Result;
00271 mutable int *m_Refcount;
00272
00273 friend class Result::Field;
00274 const char *GetValue(size_type Row, Tuple::size_type Col) const;
00275 bool GetIsNull(size_type Row, Tuple::size_type Col) const;
00276 Field::size_type GetLength(size_type Row, Tuple::size_type Col) const;
00277
00278 friend class Connection_base;
00279 explicit Result(PGresult *rhs) : m_Result(rhs), m_Refcount(0) {MakeRef(rhs);}
00280 Result &operator=(PGresult *);
00281 bool operator!() const throw () { return !m_Result; }
00282 operator bool() const throw () { return m_Result != 0; }
00283 void CheckStatus(const PGSTD::string &Query) const;
00284
00285 friend class Cursor;
00286 const char *CmdStatus() const throw () { return PQcmdStatus(m_Result); }
00287
00288
00289 void MakeRef(PGresult *);
00290 void MakeRef(const Result &);
00291 void LoseRef() throw ();
00292 };
00293
00294
00296
00303 class BinaryString : private PQAlloc<unsigned char>
00304 {
00305 typedef PQAlloc<unsigned char> super;
00306 public:
00307 typedef size_t size_type;
00308
00310
00313 explicit BinaryString(const Result::Field &F) :
00314 super(),
00315 m_size(0)
00316 {
00317 super::operator=(PQunescapeBytea(reinterpret_cast<unsigned char *>(
00318 const_cast<char *>(F.c_str())), &m_size));
00319
00320
00321 if (!c_ptr())
00322 throw std::runtime_error("Unable to read bytea field");
00323 }
00324
00326 size_type size() const throw () { return m_size; }
00327
00329 const unsigned char *bytes() const throw () { return c_ptr(); }
00330
00331 private:
00332 size_type m_size;
00333 };
00334
00335
00337
00354 template<typename STREAM>
00355 inline STREAM &operator<<(STREAM &S, const pqxx::Result::Field &F)
00356 {
00357 S << F.c_str();
00358 return S;
00359 }
00360
00361
00362
00363 inline Result::Field
00364 Result::Tuple::operator[](Result::Tuple::size_type i) const
00365 {
00366 return Field(*this, i);
00367 }
00368
00369 inline Result::Tuple::size_type Result::Tuple::size() const
00370 {
00371 return m_Home->Columns();
00372 }
00373
00374 inline const char *Result::Field::Name() const
00375 {
00376 return m_Home->ColumnName(m_Col);
00377 }
00378
00380 template<>
00381 inline bool Result::Field::to<PGSTD::string>(PGSTD::string &Obj) const
00382 {
00383 if (is_null()) return false;
00384 Obj = c_str();
00385 return true;
00386 }
00387
00389
00392 template<>
00393 inline bool Result::Field::to<const char *>(const char *&Obj) const
00394 {
00395 if (is_null()) return false;
00396 Obj = c_str();
00397 return true;
00398 }
00399
00400
00401 inline Result::const_iterator
00402 Result::const_iterator::operator+(difference_type o) const
00403 {
00404 return const_iterator(m_Home, m_Index + o);
00405 }
00406
00407 inline Result::const_iterator
00408 operator+(Result::const_iterator::difference_type o,
00409 Result::const_iterator i)
00410 {
00411 return i + o;
00412 }
00413
00414 inline Result::const_iterator
00415 Result::const_iterator::operator-(difference_type o) const
00416 {
00417 return const_iterator(m_Home, m_Index - o);
00418 }
00419
00420 inline Result::const_iterator::difference_type
00421 Result::const_iterator::operator-(const_iterator i) const
00422 {
00423 return num()-i.num();
00424 }
00425
00426 inline Result::const_iterator Result::end() const
00427 {
00428 return const_iterator(this, size());
00429 }
00430
00431 }
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00453 #endif
00454