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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, 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[](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(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
00088
00091 class PQXX_LIBEXPORT Field : private Tuple
00092 {
00093 public:
00094 using Tuple::size_type;
00095
00096 Field(const Tuple &R, Tuple::size_type C) : Tuple(R), m_Col(C) {}
00097
00099 const char *c_str() const {return m_Home->GetValue(m_Index,m_Col);}
00100
00102 inline const char *Name() const;
00103
00105 template<typename T> bool to(T &Obj) const
00106 {
00107 if (is_null())
00108 return false;
00109
00110 try
00111 {
00112 FromString(c_str(), Obj);
00113 }
00114 catch (const PGSTD::exception &e)
00115 {
00116 throw PGSTD::runtime_error("Error reading field " +
00117 PGSTD::string(Name()) +
00118 ": " +
00119 e.what());
00120 }
00121 return true;
00122 }
00123
00124 #ifdef NO_PARTIAL_CLASS_TEMPLATE_SPECIALISATION
00125
00126 template<> bool to(PGSTD::string &Obj) const
00127 {
00128 if (is_null())
00129 return false;
00130 Obj = c_str();
00131 return true;
00132 }
00133
00135
00138 template<> bool to(const char *&Obj) const
00139 {
00140 if (is_null())
00141 return false;
00142 Obj = c_str();
00143 return true;
00144 }
00145 #endif
00146
00147
00149 template<typename T> bool to(T &Obj, const T &Default) const
00150 {
00151 const bool NotNull = to(Obj);
00152 if (!NotNull)
00153 Obj = Default;
00154 return NotNull;
00155 }
00156
00157 bool is_null() const { return m_Home->GetIsNull(m_Index,m_Col); }
00158
00159 int size() const { return m_Home->GetLength(m_Index,m_Col); }
00160
00161 private:
00162
00163 Tuple::size_type m_Col;
00164 };
00165
00166
00168
00172 class PQXX_LIBEXPORT const_iterator :
00173 public PGSTD::iterator<PGSTD::random_access_iterator_tag,
00174 const Tuple,
00175 Result::size_type>,
00176 public Tuple
00177 {
00178 public:
00179
00186 pointer operator->() const { return this; }
00187 reference operator*() const { return *operator->(); }
00188
00189 const_iterator operator++(int);
00190 const_iterator &operator++() { ++m_Index; return *this; }
00191 const_iterator operator--(int);
00192 const_iterator &operator--() { --m_Index; return *this; }
00193
00194 const_iterator &operator+=(difference_type i)
00195 { m_Index+=i; return *this; }
00196 const_iterator &operator-=(difference_type i)
00197 { m_Index-=i; return *this; }
00198
00199 bool operator==(const const_iterator &i) const
00200 {return m_Index==i.m_Index;}
00201 bool operator!=(const const_iterator &i) const
00202 {return m_Index!=i.m_Index;}
00203 bool operator<(const const_iterator &i) const
00204 {return m_Index<i.m_Index;}
00205 bool operator<=(const const_iterator &i) const
00206 {return m_Index<=i.m_Index;}
00207 bool operator>(const const_iterator &i) const
00208 {return m_Index>i.m_Index;}
00209 bool operator>=(const const_iterator &i) const
00210 {return m_Index>=i.m_Index;}
00211
00212 inline const_iterator operator+(difference_type o) const;
00213
00214 friend const_iterator operator+(difference_type o,
00215 const_iterator i);
00216
00217 inline const_iterator operator-(difference_type o) const;
00218
00219 inline difference_type operator-(const_iterator i) const;
00220
00221 Result::size_type num() const { return Row(); }
00222
00223 private:
00224 friend class Result;
00225 const_iterator(const Result *r, Result::size_type i) : Tuple(r, i) {}
00226 };
00227
00228 const_iterator begin() const { return const_iterator(this, 0); }
00229 inline const_iterator end() const;
00230
00231
00232 size_type size() const { return m_Result ? PQntuples(m_Result) : 0; }
00233 bool empty() const { return !m_Result || !PQntuples(m_Result); }
00234 size_type capacity() const { return size(); }
00235
00236 const Tuple operator[](size_type i) const { return Tuple(this, i); }
00237 const Tuple at(size_type i) const;
00238
00239 void clear() { LoseRef(); }
00240
00241 Tuple::size_type Columns() const { return PQnfields(m_Result); }
00242
00244 Tuple::size_type ColumnNumber(const char Name[]) const
00245 {return PQfnumber(m_Result,Name);}
00247 Tuple::size_type ColumnNumber(std::string Name) const
00248 {return ColumnNumber(Name.c_str());}
00249 const char *ColumnName(Tuple::size_type Number) const
00250 {return PQfname(m_Result,Number);}
00251
00253
00254 Oid InsertedOid() const { return PQoidValue(m_Result); }
00255
00256 private:
00257 PGresult *m_Result;
00258 mutable int *m_Refcount;
00259
00260 friend class Result::Field;
00261 const char *GetValue(size_type Row, Tuple::size_type Col) const;
00262 bool GetIsNull(size_type Row, Tuple::size_type Col) const;
00263 Field::size_type GetLength(size_type Row, Tuple::size_type Col) const;
00264
00265 friend class Connection;
00266 explicit Result(PGresult *rhs) : m_Result(rhs), m_Refcount(0) {MakeRef(rhs);}
00267 Result &operator=(PGresult *);
00268 bool operator!() const { return !m_Result; }
00269 operator bool() const { return m_Result != 0; }
00270 void CheckStatus() const;
00271
00272
00273 void MakeRef(PGresult *);
00274 void MakeRef(const Result &);
00275 void LoseRef() throw ();
00276 };
00277
00278
00279 inline Result::Field
00280 Result::Tuple::operator[](Result::Tuple::size_type i) const
00281 {
00282 return Field(*this, i);
00283 }
00284
00285 inline Result::Tuple::size_type Result::Tuple::size() const
00286 {
00287 return m_Home->Columns();
00288 }
00289
00290 inline const char *Result::Field::Name() const
00291 {
00292 return m_Home->ColumnName(m_Col);
00293 }
00294
00295
00296 #ifndef NO_PARTIAL_CLASS_TEMPLATE_SPECIALISATION
00297
00298 template<> inline bool Result::Field::to(PGSTD::string &Obj) const
00299 {
00300 if (is_null())
00301 return false;
00302 Obj = c_str();
00303 return true;
00304 }
00305
00307
00310 template<> inline bool Result::Field::to(const char *&Obj) const
00311 {
00312 if (is_null())
00313 return false;
00314 Obj = c_str();
00315 return true;
00316 }
00317 #endif
00318
00319
00320
00321 inline Result::const_iterator
00322 Result::const_iterator::operator+(difference_type o) const
00323 {
00324 return const_iterator(m_Home, m_Index + o);
00325 }
00326
00327 inline Result::const_iterator
00328 operator+(Result::const_iterator::difference_type o,
00329 Result::const_iterator i)
00330 {
00331 return i + o;
00332 }
00333
00334 inline Result::const_iterator
00335 Result::const_iterator::operator-(difference_type o) const
00336 {
00337 return const_iterator(m_Home, m_Index - o);
00338 }
00339
00340 inline Result::const_iterator::difference_type
00341 Result::const_iterator::operator-(const_iterator i) const
00342 {
00343 return num()-i.num();
00344 }
00345
00346 inline Result::const_iterator Result::end() const
00347 {
00348 return const_iterator(this, size());
00349 }
00350
00351 }
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00372 #endif
00373