impl/sqlite3_traits.hpp

   1 /*
   2   Sqlite3 C++ traits for sqlgg
   3   by ygrek
   4   2014-06-08
   5
   6   This is free and unencumbered software released into the public domain.
   7
   8   Anyone is free to copy, modify, publish, use, compile, sell, or
   9   distribute this software, either in source code form or as a compiled
  10   binary, for any purpose, commercial or non-commercial, and by any
  11   means.
  12
  13   For more information, please refer to <http://unlicense.org/>
  14 */
  15
  16 #include <sqlite3.h>
  17 #if defined(_UNICODE)
  18 #define TCHAR wchar_t
  19 #define SQLGG_STR(x) L##x
  20 #else
  21 #define TCHAR char
  22 #define SQLGG_STR(x) x
  23 #endif
  24 #include <assert.h>
  25 #include <stdio.h>
  26 #include <string>
  27
  28 struct sqlite3_traits
  29 {
  30   typedef int Int;
  31   typedef std::basic_string<TCHAR> Text;
  32   typedef Text Any;
  33
  34   typedef sqlite3_stmt* row;
  35   typedef sqlite3* connection;
  36
  37   static void get_column_Int(row r, int index, Int& val)
  38   {
  39      val = sqlite3_column_int(r, index);
  40   }
  41
  42   static void get_column_Text(row r, int index, Text& val)
  43   {
  44   #if defined(_UNICODE) || defined(UNICODE)
  45      val = (const TCHAR*)sqlite3_column_text16(r, index);
  46   #else
  47      val = (const TCHAR*)sqlite3_column_text(r, index);
  48   #endif
  49   }
  50
  51   static void set_param(row r, const Text& val, int index)
  52   {
  53   #if defined(_UNICODE) || defined(UNICODE)
  54       int nResult = sqlite3_bind_text16(r, index + 1, val.c_str(), -1, SQLITE_TRANSIENT);
  55   #else
  56       int nResult = sqlite3_bind_text(r, index + 1, val.c_str(), -1, SQLITE_TRANSIENT);
  57   #endif
  58       assert(SQLITE_OK == nResult);
  59   }
  60
  61   static void set_param(row r, const Int& val, int index)
  62   {
  63       int nResult = sqlite3_bind_int(r, index + 1, val);
  64       assert(SQLITE_OK == nResult);
  65   }
  66
  67   class statement
  68   {
  69   private:
  70     row stmt;
  71     connection db;
  72     TCHAR const* sql;
  73
  74   public:
  75     statement(connection db, TCHAR const* sql) : db(db), sql(sql)
  76     {
  77       stmt = NULL;
  78     }
  79
  80     void finish()
  81     {
  82       if (NULL != stmt)
  83       {
  84         sqlite3_finalize(stmt);
  85         stmt = NULL;
  86       }
  87     }
  88
  89     virtual ~statement()
  90     {
  91       finish();
  92     }
  93
  94     bool prepare()
  95     {
  96       if (NULL != stmt)
  97       {
  98         return true; // already prepared
  99       }
 100
 101       int nResult;
 102       TCHAR const* pszTail;
 103 #if defined(_UNICODE) || defined(UNICODE)
 104       nResult = sqlite3_prepare16(db, sql, -1, &stmt, (void const**)&pszTail);
 105 #else
 106       nResult = sqlite3_prepare(db, sql, -1, &stmt, &pszTail);
 107 #endif
 108
 109       if (SQLITE_OK != nResult)
 110       {
 111 #if defined(SQLGG_DEBUG)
 112         printf("sqlite3_prepare error (%u):%s\n%s\n",nResult,sqlite3_errmsg(db),sql);
 113 #endif
 114         assert(false);
 115         return false;
 116       }
 117
 118       return true;
 119     }
 120
 121     template<class T, class Binder, class Params>
 122     bool select(T result, Binder binder, Params params)
 123     {
 124       prepare();
 125
 126       if (NULL == stmt)
 127       {
 128         assert(false);
 129         return false;
 130       }
 131
 132       sqlite3_reset(stmt);
 133       sqlite3_clear_bindings(stmt);
 134
 135       params.set_params(stmt);
 136
 137       while (SQLITE_ROW == sqlite3_step(stmt)) // iterate all objects
 138       {
 139           binder.get(stmt,result);
 140       }
 141
 142       return true;
 143     }
 144
 145     template<class Params>
 146     int execute(Params params)
 147     {
 148       int nResult;
 149
 150       prepare();
 151
 152       if (NULL == stmt)
 153       {
 154         assert(false);
 155         return false;
 156       }
 157
 158       sqlite3_reset(stmt);
 159       sqlite3_clear_bindings(stmt);
 160
 161       params.set_params(stmt);
 162
 163       //Execute the command
 164       nResult = sqlite3_step(stmt);
 165       assert(SQLITE_DONE == nResult);
 166
 167       return nResult;
 168     }
 169
 170   }; // statement
 171
 172   struct no_params
 173   {
 174     void set_params(row) {}
 175   };
 176
 177 }; // sqlite3_traits