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     FieldDef()
  35     {
  36         init();
  37     }
  38     void init() {
  39         type_ = typeUnknown;
  40         length_ = 0;
  41         bindVal_ = NULL;
  42         isDefault_ = false;
  43         isNull_ = false;
  44     }
  45     char fldName_[IDENTIFIER_LENGTH];
  46     DataType type_;
  47     size_t length_;
  48     //currently default value is supported for string and binary
  49     //less than length 32 bytes
  50     char defaultValueBuf_[DEFAULT_VALUE_BUF_LENGTH];
  51
  52     //used only in case of binding fields
  53     void *bindVal_;
  54
  55     bool isNull_;
  56     bool isPrimary_;
  57     bool isDefault_;
  58     bool isUnique_;
  59     //TODO::width and scale
  60 };
  61
  62 class FieldNode
  63 {
  64     public:
  65     FieldDef fldDef;
  66     FieldNode *next;
  67 };
  68
  69
  70 class FieldIterator
  71 {
  72     public:
  73     FieldNode *iter;
  74     FieldIterator(FieldNode *ptr) { iter = ptr; }
  75     bool hasElement()
  76     {
  77         if (iter == NULL) return false; else return true;
  78     }
  79     FieldDef nextElement()
  80     {
  81         if (iter == NULL) { FieldDef dummyDef; return dummyDef;}
  82         FieldNode *node = iter;
  83         iter = iter ->next;
  84         return node->fldDef;
  85     }
  86 };
  87
  88 class FieldInfo;
  89
  90 //Internal class used to implement the field list information
  91 //to create the table
  92 class FieldList
  93 {
  94     public:
  95     FieldNode *head;
  96     FieldList(){ head = NULL;}
  97
  98     //TODO::pass by reference instead of value
  99     DbRetVal append(FieldDef fDef);
 100
 101     DbRetVal remove(const char* fldName);
 102
 103     DbRetVal removeAll();
 104
 105     DbRetVal updateBindVal(const char *fldName, void *val);
 106
 107     int getFieldOffset(const char *fldName);
 108     int getFieldOffset(int fldpos);
 109
 110     DataType getFieldType(const char *fldName);
 111
 112     size_t getFieldLength(const char *fldName);
 113
 114     DbRetVal getFieldInfo(const char *fldName, FieldInfo *&info);
 115
 116     int getTupleSize();
 117
 118     FieldIterator getIterator()
 119     {
 120         FieldIterator iter(head);
 121         return iter;
 122     }
 123 };
 124 #endif