mysqlquery.cpp

C++连接一写常用数据库的接口

/*
 * MysqQuery object defines the needed query functions for the dbConnect MySQL driver
 * Copyright (C) 2002 Johnathan Ingram, [e-mail]
 *
 * This library is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *   Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  US
 *
 */

#include "mysqlQuery.h"

#include <time.h>
#include <string.h>

#include "mysqlConnection.h"
#include "dbconnectTypes.h"

// -----------------------------------------------------------------------------
// PRIVATE:
// -----------------------------------------------------------------------------

//------------------------------------------------------------------------------
// MysqlQuery::_mysqGetFieldsInformation
//------------------------------------------------------------------------------
void 
MysqlQuery::_mysqlGetFieldsInformation()
{
   // Clear any previouse field information just incase.
   _freeCollection(FIELD_INFORMATION);

   // Internal method used to build the field information.
   MYSQL_FIELD *field_prop = NULL;

   
   // Allocate the information pointers
   _numFieldInformation = _fieldCount;
   _fieldInformation = (BaseFieldDescription**)malloc(_numFieldInformation * sizeof(BaseFieldDescription*));
   
   // Assign the data to the corresponding fields.
   for (int i=0; i<_numFieldInformation; i++)
   {
      field_prop = mysql_fetch_field(__mysql_res__);
 
      if (field_prop != NULL)
      {
         // Field Name.
         string fName = field_prop->name;
      
         // Work out the field type.
         FieldType _type = _mysqlResolveFieldType(field_prop->type);

         // Field Properties.
      	long int  _precision = 0;
         long int  _scale = 0;

         bool     _isIncrement = field_prop->flags & AUTO_INCREMENT_FLAG;
         bool     _isPriKey    = field_prop->flags & PRI_KEY_FLAG;
         bool     _isUnique    = field_prop->flags & UNIQUE_KEY_FLAG;
         bool     _isNotNull   = field_prop->flags & NOT_NULL_FLAG;

         if (_type == FT_DOUBLE)
         {
            _precision = field_prop->max_length;  //Seems to work for the precision.
            _scale = field_prop->decimals;
         }

         // Add the field properties to the vector.
         _fieldInformation[i] = new BaseFieldDescription(fName, i, _type, _isIncrement, _isPriKey, _isUnique, _isNotNull);
      }
   }
}  // MysqlQuery::_mysqGetFieldsInformation


//------------------------------------------------------------------------------
// MysqlQuery::_mysqlGetResultSetRow
//------------------------------------------------------------------------------
void
MysqlQuery::_mysqlGetResultSetRow()
{
   // Free the current field values just incase
   _freeCollection(FIELD_VALUES);
   
   // Retrieve the data from the current row.
   MYSQL_ROW     row_data;
   unsigned long *row_lengths;    // Unsigned long as this is how the function is defined

   try
   {
      // Fetch the row and data sizes and advance the cursor with mysql_fetch_row.
      row_data = mysql_fetch_row(__mysql_res__);
      row_lengths = mysql_fetch_lengths(__mysql_res__);

      // Allocate the value pointers
      _numRecordValues = _fieldCount;
      _recordValues = (MysqlValue**)malloc(_numRecordValues * sizeof(MysqlValue*));
            
      // Assign the data to the corresponding fields.
      for (int i=0; i<_numRecordValues; i++)
      {
         // Allocate the field
         _recordValues[i] = new MysqlValue(_fieldInformation[i]->name().c_str());
         
			// Check if the field is NULL
         if (row_data[i] == NULL)
         {
            _recordValues[i]->setNULL();
         }
         else
         {
            char* data = (char*)malloc(row_lengths[i] + 1);
            strncpy(data, row_data[i], row_lengths[i]);

            if (_fieldInformation[i]->type() == FT_BLOB)
            {
               // BLOB type, set it as a Binary field and do not free the memory as the MysqlValue Object will
               _recordValues[i]->setBinary((void*)data, row_lengths[i]);
            }
            else
            {                
               // Need to first convert the MySQL result to a NULL terminating string
               data[row_lengths[i]] = '\0';
               _recordValues[i]->setString((const char*)data);
               free((void*)data);
            }
         }
		}
   }
   catch(...)
   { }
}  // MysqlQuery::_mysqlGetResultSetRow


//------------------------------------------------------------------------------
// MysqlQuery::_mysqlResolveFieldType
//------------------------------------------------------------------------------
FieldType
MysqlQuery::_mysqlResolveFieldType(
   enum_field_types type)
{
   FieldType res;
   
   switch(type)
   {
      case FIELD_TYPE_TINY:
         res = FT_SHORT;
         break;      
      case FIELD_TYPE_SHORT:
         res = FT_SHORT;
         break;      
      case FIELD_TYPE_LONG:
         res = FT_LONG;
         break;      
      case FIELD_TYPE_INT24:
         res = FT_LONG;
         break;      
      case FIELD_TYPE_LONGLONG:
         res = FT_LONG;
         break;      
      case FIELD_TYPE_DECIMAL:
         res = FT_DOUBLE;
         break;      
      case FIELD_TYPE_FLOAT:
         res = FT_DOUBLE;
         break;      
      case FIELD_TYPE_DOUBLE:
         res = FT_DOUBLE;
         break;      
      case FIELD_TYPE_TIMESTAMP:
         res = FT_DATETIME;
         break;      
      case FIELD_TYPE_DATE:
         res = FT_DATETIME;
         break;      
      case FIELD_TYPE_TIME:
         res = FT_DATETIME;
         break;      
      case FIELD_TYPE_DATETIME:
         res = FT_DATETIME;
         break;      
      case FIELD_TYPE_YEAR:
         res = FT_DATETIME;
         break;      
      case FIELD_TYPE_STRING:
         res = FT_STRING;
         break;      
      case FIELD_TYPE_BLOB:
         res = FT_BLOB;
         break;      
      case FIELD_TYPE_TINY_BLOB:
         res = FT_BLOB;
         break;      
      case FIELD_TYPE_MEDIUM_BLOB:
         res = FT_BLOB;
         break;      
      case FIELD_TYPE_LONG_BLOB:
         res = FT_BLOB;
         break;      
      case FIELD_TYPE_SET:
         res = FT_STRING;
         break;      
      case FIELD_TYPE_ENUM:
         res = FT_STRING;
         break;      
      case FIELD_TYPE_NULL:
         res = FT_NULL;
         break;      
      case FIELD_TYPE_VAR_STRING:
         res = FT_STRING;    
         break;      
      default:
         res = FT_UNKNOWN;
         break;      
   }
   
   return res;
}  // MysqlQuery::_mysqlResolveFieldType
  

//------------------------------------------------------------------------------
// MysqlQuery::_mysqlParseBindParameters
//------------------------------------------------------------------------------
string
MysqlQuery::_mysqlParseBindParameters(
      const string& originalSqlStatement)

{
   // Try and substitute the parameters checking to make sure they exist.
   string res = originalSqlStatement; 
   int pos;
   
   for (int i =0; i<_numParameters; i++)
   {
      string paramName = ":" + _parameters[i]->name();
      if ((pos = res.find(paramName)) == string::npos)
      {
         // We have a parameter that is not present in our sql statement
         string err = "_mysqlParseBindParameters(): The specified bind parameter, ";
         err += paramName;
         err += ", is not present in the SQL statement: ";
         err += originalSqlStatement;
         throw BindParameterNotPresent(err);
      }
      
      // Substitute the parameter with the correct value according to the parameter type.
      res.replace(pos, paramName.length(), _parameters[i]->paramToMySQLString());
   }
   
   // Make sure there are no parameters left
   if (((pos = res.find(" :")) != string::npos) || 
       ((pos = res.find("(:")) != string::npos) || 
       ((pos = res.find(",:")) != string::npos) )
   {
      // We have a parameter that has not been set.
      pos += 1;
      int pos2 = res.find(" ", pos);
      int pos3 = res.find(")", pos);
      int pos4 = res.find(",", pos);
      if (pos2 == string::npos) pos2 = 65535;
      if (pos3 == string::npos) pos3 = 65535;
      if (pos4 == string::npos) pos4 = 65535;         
      
      int endPos;      
      if (pos2 < pos3 && pos2 < pos4)
         endPos = pos2;
      if (pos3 < pos2 && pos3 < pos4)
         endPos = pos3;
      if (pos4 < pos2 && pos4 < pos3)
         endPos = pos4;     
      
      string unknownParam = res.substr(pos, endPos-pos);
      
      string err = "_mysqlParseBindParameters(): The bind parameter, ";
      err += unknownParam;
      err += ", in the SQL statement: ";
      err += originalSqlStatement;
      err += " has not been set.";
      throw BindParameterNotSet(err);
   }
   
   return res;
}  // MysqlQuery::_mysqlParseBindParameters


//------------------------------------------------------------------------------
// MysqlQuery::_freeCollection
//------------------------------------------------------------------------------
void 
MysqlQuery::_freeCollection(
   CollectionType type)
{
   int i;
   switch (type)
   {
      case FIELD_INFORMATION:
         if (_fieldInformation)
         {
            for (i=0; i<_numFieldInformation; i++)
            {
               if (_fieldInformation[i])
               {
                  delete _fieldInformation[i];
                  _fieldInformation[i] = NULL;         
               }
            }
            free(_fieldInformation);
            _fieldInformation = NULL;
            _numFieldInformation = 0;
            _fieldCount = 0;            
         }
      
         break;
      
      
      case FIELD_VALUES:
         if (_recordValues)
         {
            for (i=0; i<_numRecordValues; i++)
            {
               if (_recordValues[i])
               {
                  delete _recordValues[i];
                  _recordValues[i] = NULL;         
               }
            }
            free(_recordValues);
            _recordValues = NULL;
            _numRecordValues = 0;
         }
       
         break;
         
      case BIND_PARAMETERS:
         if (_parameters)
         {
            for (i=0; i<_numParameters; i++)
            {
               if (_parameters[i])
               {
                  delete _parameters[i];
                  _parameters[i] = NULL;         
               }
            }
            free(_parameters);
            _parameters = NULL;
            _numParameters = 0;
         }
               
         break;      
   }
}  // MysqlQuery::_freeCollection


// -----------------------------------------------------------------------------
// PUBLIC:
// -----------------------------------------------------------------------------


//------------------------------------------------------------------------------
// MysqlQuery::MysqlQuery
//------------------------------------------------------------------------------
MysqlQuery::MysqlQuery(
   MysqlConnection* parentConnection,
   int              index)
: 
   _parentConnection(parentConnection),
   _index(index),
   _isTransaction(false),
   __mysql_res__(NULL),
   _mysqlNumRows(0),