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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 const_iterator() : Tuple(0,0) {}
00182
00189 pointer operator->() const { return this; }
00190 reference operator*() const { return *operator->(); }
00191
00192 const_iterator operator++(int);
00193 const_iterator &operator++() { ++m_Index; return *this; }
00194 const_iterator operator--(int);
00195 const_iterator &operator--() { --m_Index; return *this; }
00196
00197 const_iterator &operator+=(difference_type i)
00198 { m_Index+=i; return *this; }
00199 const_iterator &operator-=(difference_type i)
00200 { m_Index-=i; return *this; }
00201
00202 bool operator==(const const_iterator &i) const
00203 {return m_Index==i.m_Index;}
00204 bool operator!=(const const_iterator &i) const
00205 {return m_Index!=i.m_Index;}
00206 bool operator<(const const_iterator &i) const
00207 {return m_Index<i.m_Index;}
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
00215 inline const_iterator operator+(difference_type o) const;
00216
00217 friend const_iterator operator+(difference_type o,
00218 const_iterator i);
00219
00220 inline const_iterator operator-(difference_type o) const;
00221
00222 inline difference_type operator-(const_iterator i) const;
00223
00224 Result::size_type num() const { return Row(); }
00225
00226 private:
00227 friend class Result;
00228 const_iterator(const Result *r, Result::size_type i) : Tuple(r, i) {}
00229 };
00230
00231 const_iterator begin() const { return const_iterator(this, 0); }
00232 inline const_iterator end() const;
00233
00234
00235 size_type size() const { return m_Result ? PQntuples(m_Result) : 0; }
00236 bool empty() const { return !m_Result || !PQntuples(m_Result); }
00237 size_type capacity() const { return size(); }
00238
00239 const Tuple operator[](size_type i) const { return Tuple(this, i); }
00240 const Tuple at(size_type) const;
00241
00242 void clear() { LoseRef(); }
00243
00244 Tuple::size_type Columns() const { return PQnfields(m_Result); }
00245
00247 Tuple::size_type ColumnNumber(const char Name[]) const
00248 {return PQfnumber(m_Result,Name);}
00250 Tuple::size_type ColumnNumber(const std::string &Name) const
00251 {return ColumnNumber(Name.c_str());}
00252 const char *ColumnName(Tuple::size_type Number) const
00253 {return PQfname(m_Result,Number);}
00254
00256
00257 Oid InsertedOid() const { return PQoidValue(m_Result); }
00258
00260
00261 size_type AffectedRows() const;
00262
00263 private:
00264 PGresult *m_Result;
00265 mutable int *m_Refcount;
00266
00267 friend class Result::Field;
00268 const char *GetValue(size_type Row, Tuple::size_type Col) const;
00269 bool GetIsNull(size_type Row, Tuple::size_type Col) const;
00270 Field::size_type GetLength(size_type Row, Tuple::size_type Col) const;
00271
00272 friend class ConnectionItf;
00273 explicit Result(PGresult *rhs) : m_Result(rhs), m_Refcount(0) {MakeRef(rhs);}
00274 Result &operator=(PGresult *);
00275 bool operator!() const throw () { return !m_Result; }
00276 operator bool() const throw () { return m_Result != 0; }
00277 void CheckStatus(const PGSTD::string &Query) const;
00278
00279 friend class Cursor;
00280 const char *CmdStatus() const throw () { return PQcmdStatus(m_Result); }
00281
00282
00283 void MakeRef(PGresult *);
00284 void MakeRef(const Result &);
00285 void LoseRef() throw ();
00286 };
00287
00288
00289 inline Result::Field
00290 Result::Tuple::operator[](Result::Tuple::size_type i) const
00291 {
00292 return Field(*this, i);
00293 }
00294
00295 inline Result::Tuple::size_type Result::Tuple::size() const
00296 {
00297 return m_Home->Columns();
00298 }
00299
00300 inline const char *Result::Field::Name() const
00301 {
00302 return m_Home->ColumnName(m_Col);
00303 }
00304
00306 template<>
00307 inline bool Result::Field::to<PGSTD::string>(PGSTD::string &Obj) const
00308 {
00309 if (is_null()) return false;
00310 Obj = c_str();
00311 return true;
00312 }
00313
00315
00318 template<>
00319 inline bool Result::Field::to<const char *>(const char *&Obj) const
00320 {
00321 if (is_null()) return false;
00322 Obj = c_str();
00323 return true;
00324 }
00325
00326
00327 inline Result::const_iterator
00328 Result::const_iterator::operator+(difference_type o) const
00329 {
00330 return const_iterator(m_Home, m_Index + o);
00331 }
00332
00333 inline Result::const_iterator
00334 operator+(Result::const_iterator::difference_type o,
00335 Result::const_iterator i)
00336 {
00337 return i + o;
00338 }
00339
00340 inline Result::const_iterator
00341 Result::const_iterator::operator-(difference_type o) const
00342 {
00343 return const_iterator(m_Home, m_Index - o);
00344 }
00345
00346 inline Result::const_iterator::difference_type
00347 Result::const_iterator::operator-(const_iterator i) const
00348 {
00349 return num()-i.num();
00350 }
00351
00352 inline Result::const_iterator Result::end() const
00353 {
00354 return const_iterator(this, size());
00355 }
00356
00357 }
00358
00359
00361
00378 template<typename STREAM>
00379 inline STREAM &operator<<(STREAM &S, const pqxx::Result::Field &F)
00380 {
00381 S << F.c_str();
00382 return S;
00383 }
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00405 #endif
00406