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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>(PGSTD::string &Obj) const;
00141
00143
00146 template<> bool to<const char *>(const char *&Obj) const;
00147 #endif
00148
00149
00151 template<typename T> bool to(T &Obj, const T &Default) const
00152 {
00153 const bool NotNull = to(Obj);
00154 if (!NotNull)
00155 Obj = Default;
00156 return NotNull;
00157 }
00158
00159 bool is_null() const { return m_Home->GetIsNull(m_Index,m_Col); }
00160
00161 int size() const { return m_Home->GetLength(m_Index,m_Col); }
00162
00163 private:
00164
00165 Tuple::size_type m_Col;
00166 };
00167
00168
00170
00174 class PQXX_LIBEXPORT const_iterator :
00175 public PGSTD::iterator<PGSTD::random_access_iterator_tag,
00176 const Tuple,
00177 Result::size_type>,
00178 public Tuple
00179 {
00180 public:
00181
00188 pointer operator->() const { return this; }
00189 reference operator*() const { return *operator->(); }
00190
00191 const_iterator operator++(int);
00192 const_iterator &operator++() { ++m_Index; return *this; }
00193 const_iterator operator--(int);
00194 const_iterator &operator--() { --m_Index; return *this; }
00195
00196 const_iterator &operator+=(difference_type i)
00197 { m_Index+=i; return *this; }
00198 const_iterator &operator-=(difference_type i)
00199 { m_Index-=i; return *this; }
00200
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 bool operator>=(const const_iterator &i) const
00212 {return m_Index>=i.m_Index;}
00213
00214 inline const_iterator operator+(difference_type o) const;
00215
00216 friend const_iterator operator+(difference_type o,
00217 const_iterator i);
00218
00219 inline const_iterator operator-(difference_type o) const;
00220
00221 inline difference_type operator-(const_iterator i) const;
00222
00223 Result::size_type num() const { return Row(); }
00224
00225 private:
00226 friend class Result;
00227 const_iterator(const Result *r, Result::size_type i) : Tuple(r, i) {}
00228 };
00229
00230 const_iterator begin() const { return const_iterator(this, 0); }
00231 inline const_iterator end() const;
00232
00233
00234 size_type size() const { return m_Result ? PQntuples(m_Result) : 0; }
00235 bool empty() const { return !m_Result || !PQntuples(m_Result); }
00236 size_type capacity() const { return size(); }
00237
00238 const Tuple operator[](size_type i) const { return Tuple(this, i); }
00239 const Tuple at(size_type) const;
00240
00241 void clear() { LoseRef(); }
00242
00243 Tuple::size_type Columns() const { return PQnfields(m_Result); }
00244
00246 Tuple::size_type ColumnNumber(const char Name[]) const
00247 {return PQfnumber(m_Result,Name);}
00249 Tuple::size_type ColumnNumber(const std::string &Name) const
00250 {return ColumnNumber(Name.c_str());}
00251 const char *ColumnName(Tuple::size_type Number) const
00252 {return PQfname(m_Result,Number);}
00253
00255
00256 Oid InsertedOid() const { return PQoidValue(m_Result); }
00257
00259
00260 size_type AffectedRows() const;
00261
00262 private:
00263 PGresult *m_Result;
00264 mutable int *m_Refcount;
00265
00266 friend class Result::Field;
00267 const char *GetValue(size_type Row, Tuple::size_type Col) const;
00268 bool GetIsNull(size_type Row, Tuple::size_type Col) const;
00269 Field::size_type GetLength(size_type Row, Tuple::size_type Col) const;
00270
00271 friend class ConnectionItf;
00272 explicit Result(PGresult *rhs) : m_Result(rhs), m_Refcount(0) {MakeRef(rhs);}
00273 Result &operator=(PGresult *);
00274 bool operator!() const throw () { return !m_Result; }
00275 operator bool() const throw () { return m_Result != 0; }
00276 void CheckStatus() const;
00277
00278 friend class Cursor;
00279 const char *CmdStatus() const throw () { return PQcmdStatus(m_Result); }
00280
00281
00282 void MakeRef(PGresult *);
00283 void MakeRef(const Result &);
00284 void LoseRef() throw ();
00285 };
00286
00287
00288 inline Result::Field
00289 Result::Tuple::operator[](Result::Tuple::size_type i) const
00290 {
00291 return Field(*this, i);
00292 }
00293
00294 inline Result::Tuple::size_type Result::Tuple::size() const
00295 {
00296 return m_Home->Columns();
00297 }
00298
00299 inline const char *Result::Field::Name() const
00300 {
00301 return m_Home->ColumnName(m_Col);
00302 }
00303
00305 template<>
00306 inline bool Result::Field::to<PGSTD::string>(PGSTD::string &Obj) const
00307 {
00308 if (is_null()) return false;
00309 Obj = c_str();
00310 return true;
00311 }
00312
00314
00317 template<>
00318 inline bool Result::Field::to<const char *>(const char *&Obj) const
00319 {
00320 if (is_null()) return false;
00321 Obj = c_str();
00322 return true;
00323 }
00324
00325
00326 inline Result::const_iterator
00327 Result::const_iterator::operator+(difference_type o) const
00328 {
00329 return const_iterator(m_Home, m_Index + o);
00330 }
00331
00332 inline Result::const_iterator
00333 operator+(Result::const_iterator::difference_type o,
00334 Result::const_iterator i)
00335 {
00336 return i + o;
00337 }
00338
00339 inline Result::const_iterator
00340 Result::const_iterator::operator-(difference_type o) const
00341 {
00342 return const_iterator(m_Home, m_Index - o);
00343 }
00344
00345 inline Result::const_iterator::difference_type
00346 Result::const_iterator::operator-(const_iterator i) const
00347 {
00348 return num()-i.num();
00349 }
00350
00351 inline Result::const_iterator Result::end() const
00352 {
00353 return const_iterator(this, size());
00354 }
00355
00356 }
00357
00358
00360
00377 template<typename STREAM>
00378 inline STREAM &operator<<(STREAM &S, const pqxx::Result::Field &F)
00379 {
00380 S << F.c_str();
00381 return S;
00382 }
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00404 #endif
00405