include/Field.h

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by www.databasecache.com                           *
   3  *   Contact: praba_tuty@databasecache.com                                 *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15   ***************************************************************************/
  16 #ifndef FIELD_H
  17 #define FIELD_H
  18 #include<os.h>
  19 #include<DataType.h>
  20 #include<ErrorType.h>
  21
  22 //used by FieldNameList
  23 class FieldNameNode
  24 {
  25     public:
  26     char  fldName[IDENTIFIER_LENGTH];
  27     FieldNameNode *next;
  28 };
  29
  30
  31 class FieldDef
  32 {
  33     public:
  34     char fldName_[IDENTIFIER_LENGTH];
  35     DataType type_;
  36     size_t length_;
  37     //currently default value is supported for string and binary
  38     //less than length 32 bytes
  39     char defaultValueBuf_[DEFAULT_VALUE_BUF_LENGTH];
  40
  41     //used only in case of binding fields
  42     void *bindVal_;
  43
  44     bool isNull_;
  45     bool isPrimary_;
  46     bool isDefault_;
  47     //TODO::width and scale
  48 };
  49
  50 class FieldNode
  51 {
  52     public:
  53     FieldDef fldDef;
  54     FieldNode *next;
  55 };
  56
  57
  58 class FieldIterator
  59 {
  60     public:
  61     FieldNode *iter;
  62     FieldIterator(FieldNode *ptr) { iter = ptr; }
  63     int hasElement()
  64     {
  65         if (iter == NULL) return -1; else return 0;
  66     }
  67     FieldDef nextElement()
  68     {
  69         if (iter == NULL) { FieldDef dummyDef; return dummyDef;}
  70         FieldNode *node = iter;
  71         iter = iter ->next;
  72         return node->fldDef;
  73     }
  74 };
  75
  76 //Internal class used to implement the field list information
  77 //to create the table
  78 class FieldList
  79 {
  80     public:
  81     FieldNode *head;
  82     FieldList(){ head = NULL;}
  83
  84     //TODO::pass by reference instead of value
  85     DbRetVal append(FieldDef fDef);
  86
  87     DbRetVal remove(const char* fldName);
  88
  89     DbRetVal removeAll();
  90
  91     DbRetVal updateBindVal(const char *fldName, void *val);
  92
  93     int getFieldOffset(const char *fldName);
  94     int getFieldOffset(int fldpos);
  95
  96     DataType getFieldType(const char *fldName);
  97
  98     size_t getFieldLength(const char *fldName);
  99
 100     int getTupleSize();
 101
 102     FieldIterator getIterator()
 103     {
 104         FieldIterator iter(head);
 105         return iter;
 106     }
 107 };
 108 #endif