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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 protected:
00082 const Result *m_Home;
00083 Result::size_type m_Index;
00084
00085
00086 Tuple();
00087 };
00088
00089
00091
00094 class PQXX_LIBEXPORT Field : private Tuple
00095 {
00096 public:
00097 typedef size_t size_type;
00098
00100
00104 Field(const Tuple &R, Tuple::size_type C) : Tuple(R), m_Col(C) {}
00105
00107
00112 const char *c_str() const {return m_Home->GetValue(m_Index,m_Col);}
00113
00115 inline const char *Name() const;
00116
00118 template<typename T> bool to(T &Obj) const
00119 {
00120 if (is_null())
00121 return false;
00122
00123 try
00124 {
00125 FromString(c_str(), Obj);
00126 }
00127 catch (const PGSTD::exception &e)
00128 {
00129 throw PGSTD::runtime_error("Error reading field " +
00130 PGSTD::string(Name()) +
00131 ": " +
00132 e.what());
00133 }
00134 return true;
00135 }
00136
00137
00138 #ifdef NO_PARTIAL_CLASS_TEMPLATE_SPECIALISATION
00139
00140 template<> bool to(PGSTD::string &Obj) const
00141 {
00142 if (is_null())
00143 return false;
00144 Obj = c_str();
00145 return true;
00146 }
00147
00149
00152 template<> bool to(const char *&Obj) const
00153 {
00154 if (is_null())
00155 return false;
00156 Obj = c_str();
00157 return true;
00158 }
00159 #endif
00160
00161
00163 template<typename T> bool to(T &Obj, const T &Default) const
00164 {
00165 const bool NotNull = to(Obj);
00166 if (!NotNull)
00167 Obj = Default;
00168 return NotNull;
00169 }
00170
00171 bool is_null() const { return m_Home->GetIsNull(m_Index,m_Col); }
00172
00173 int size() const { return m_Home->GetLength(m_Index,m_Col); }
00174
00175 private:
00176
00177 Tuple::size_type m_Col;
00178 };
00179
00180
00182
00186 class PQXX_LIBEXPORT const_iterator :
00187 public PGSTD::iterator<PGSTD::random_access_iterator_tag,
00188 const Tuple,
00189 Result::size_type>,
00190 public Tuple
00191 {
00192 public:
00193
00200 pointer operator->() const { return this; }
00201 reference operator*() const { return *operator->(); }
00202
00203 const_iterator operator++(int);
00204 const_iterator &operator++() { ++m_Index; return *this; }
00205 const_iterator operator--(int);
00206 const_iterator &operator--() { --m_Index; return *this; }
00207
00208 const_iterator &operator+=(difference_type i)
00209 { m_Index+=i; return *this; }
00210 const_iterator &operator-=(difference_type i)
00211 { m_Index-=i; return *this; }
00212
00213 bool operator==(const const_iterator &i) const
00214 {return m_Index==i.m_Index;}
00215 bool operator!=(const const_iterator &i) const
00216 {return m_Index!=i.m_Index;}
00217 bool operator<(const const_iterator &i) const
00218 {return m_Index<i.m_Index;}
00219 bool operator<=(const const_iterator &i) const
00220 {return m_Index<=i.m_Index;}
00221 bool operator>(const const_iterator &i) const
00222 {return m_Index>i.m_Index;}
00223 bool operator>=(const const_iterator &i) const
00224 {return m_Index>=i.m_Index;}
00225
00226 inline const_iterator operator+(difference_type o) const;
00227
00228 friend const_iterator operator+(difference_type o,
00229 const_iterator i);
00230
00231 inline const_iterator operator-(difference_type o) const;
00232
00233 inline difference_type operator-(const_iterator i) const;
00234
00235 Result::size_type num() const { return Row(); }
00236
00237 private:
00238 friend class Result;
00239 const_iterator(const Result *r, Result::size_type i) : Tuple(r, i) {}
00240 };
00241
00242 const_iterator begin() const { return const_iterator(this, 0); }
00243 inline const_iterator end() const;
00244
00245
00246 size_type size() const { return m_Result ? PQntuples(m_Result) : 0; }
00247 bool empty() const { return !m_Result || !PQntuples(m_Result); }
00248 size_type capacity() const { return size(); }
00249
00250 const Tuple operator[](size_type i) const { return Tuple(this, i); }
00251 const Tuple at(size_type) const;
00252
00253 void clear() { LoseRef(); }
00254
00255 Tuple::size_type Columns() const { return PQnfields(m_Result); }
00256
00258 Tuple::size_type ColumnNumber(const char Name[]) const
00259 {return PQfnumber(m_Result,Name);}
00261 Tuple::size_type ColumnNumber(const std::string &Name) const
00262 {return ColumnNumber(Name.c_str());}
00263 const char *ColumnName(Tuple::size_type Number) const
00264 {return PQfname(m_Result,Number);}
00265
00267
00268 Oid InsertedOid() const { return PQoidValue(m_Result); }
00269
00271
00272 size_type AffectedRows() const;
00273
00274 private:
00275 PGresult *m_Result;
00276 mutable int *m_Refcount;
00277
00278 friend class Result::Field;
00279 const char *GetValue(size_type Row, Tuple::size_type Col) const;
00280 bool GetIsNull(size_type Row, Tuple::size_type Col) const;
00281 Field::size_type GetLength(size_type Row, Tuple::size_type Col) const;
00282
00283 friend class Connection;
00284 explicit Result(PGresult *rhs) : m_Result(rhs), m_Refcount(0) {MakeRef(rhs);}
00285 Result &operator=(PGresult *);
00286 bool operator!() const throw () { return !m_Result; }
00287 operator bool() const throw () { return m_Result != 0; }
00288 void CheckStatus() const;
00289
00290 friend class Cursor;
00291 const char *CmdStatus() const throw () { return PQcmdStatus(m_Result); }
00292
00293
00294 void MakeRef(PGresult *);
00295 void MakeRef(const Result &);
00296 void LoseRef() throw ();
00297 };
00298
00299
00300 inline Result::Field
00301 Result::Tuple::operator[](Result::Tuple::size_type i) const
00302 {
00303 return Field(*this, i);
00304 }
00305
00306 inline Result::Tuple::size_type Result::Tuple::size() const
00307 {
00308 return m_Home->Columns();
00309 }
00310
00311 inline const char *Result::Field::Name() const
00312 {
00313 return m_Home->ColumnName(m_Col);
00314 }
00315
00316
00317 #ifndef NO_PARTIAL_CLASS_TEMPLATE_SPECIALISATION
00318
00319 template<> inline bool Result::Field::to(PGSTD::string &Obj) const
00320 {
00321 if (is_null())
00322 return false;
00323 Obj = c_str();
00324 return true;
00325 }
00326
00328
00331 template<> inline bool Result::Field::to(const char *&Obj) const
00332 {
00333 if (is_null())
00334 return false;
00335 Obj = c_str();
00336 return true;
00337 }
00338 #endif
00339
00340
00341
00342 inline Result::const_iterator
00343 Result::const_iterator::operator+(difference_type o) const
00344 {
00345 return const_iterator(m_Home, m_Index + o);
00346 }
00347
00348 inline Result::const_iterator
00349 operator+(Result::const_iterator::difference_type o,
00350 Result::const_iterator i)
00351 {
00352 return i + o;
00353 }
00354
00355 inline Result::const_iterator
00356 Result::const_iterator::operator-(difference_type o) const
00357 {
00358 return const_iterator(m_Home, m_Index - o);
00359 }
00360
00361 inline Result::const_iterator::difference_type
00362 Result::const_iterator::operator-(const_iterator i) const
00363 {
00364 return num()-i.num();
00365 }
00366
00367 inline Result::const_iterator Result::end() const
00368 {
00369 return const_iterator(this, size());
00370 }
00371
00372 }
00373
00374
00376
00393 template<typename STREAM>
00394 inline STREAM &operator<<(STREAM &S, const pqxx::Result::Field &F)
00395 {
00396 S << F.c_str();
00397 return S;
00398 }
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00420 #endif
00421