Berkeley DB是Sleepcat開發的開源的嵌入式數據庫。具有輕巧、可擴展的優點。但是它不支持SQL語句，而且操作起來相對比較復雜。
下面講講在VC下為了使其能夠存儲數據結構做的封裝。
在google搜索Berkely DB 進入sleepycat下載zip安裝包，編譯。
建立工程TestBerkeleyDB，拷貝libdb43.dll和libdb43.lib到當前工程下，添加libdb43.dll到工程的setting。
把db.h和db_cxx.h拷貝到當前目錄下。
添加icqtypes.h：
#ifndef _ICQ_TYPES_H_
#define _ICQ_TYPES_H_

#include "string"
#include "list"
#include "vector"
#include "bitset"

using namespace std;

typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned long uint32;

typedef list  StrList;
typedef list PtrList;
typedef list UinList;

#endif

添加icqdb.h;
#ifndef _ICQ_DB_H
#define _ICQ_DB_H

#include "icqtypes.h"
#include "db_cxx.h"
#define MAX_BLOCK_SIZE 4096

class DBOutStream {
public:
 DBOutStream() {
  cursor = data;
 }
 char *getData() {
  return data;
 }
 int getSize() {
  return (cursor - data);
 }

 DBOutStream &operator <<(uint8 b);
 DBOutStream &operator <<(uint16 w);
 DBOutStream &operator <<(uint32 dw);
 DBOutStream &operator <<(const char *str);
 DBOutStream &operator <<(const string &str) {
  return operator <<(str.c_str());
 }
 DBOutStream &operator <<(StrList &strList);
 
private:
 char data[MAX_BLOCK_SIZE];
 char *cursor;
};

class DBInStream {
public:
 DBInStream(void *d, int n) {
  cursor = data = (char *) d;
  datalen = n;
 }
 DBInStream &operator >>(uint8 &b);
 DBInStream &operator >>(uint16 &w);
 DBInStream &operator >>(uint32 &dw);
 DBInStream &operator >>(string &str);
 DBInStream &operator >>(StrList &strList);

private:
 char *data;
 char *cursor;
 int datalen;
};

class DBSerialize {
public:
 virtual void save(DBOutStream &out) = 0;
 virtual void load(DBInStream &in) = 0;
};


#endif
添加icqdb.cpp:
#include "stdafx.h"
#include "icqdb.h"
#include "string.h"
#include "icqtypes.h"
#define INDEX_USER  0
#define INDEX_OPTIONS 0xffffffff
#define INDEX_GROUP  0xfffffffe

DBOutStream &DBOutStream::operator <<(uint8 b)
{
 if (cursor <= data + MAX_BLOCK_SIZE - sizeof(b))
  *cursor++ = b;
 return (*this);
}

DBOutStream &DBOutStream::operator <<(uint16 w)
{
 if (cursor <= data + MAX_BLOCK_SIZE - sizeof(w)) {
  *(uint16 *) cursor = w;
  cursor += sizeof(w);
 }
 return (*this);
}

DBOutStream &DBOutStream::operator <<(uint32 dw)
{
 if (cursor <= data + MAX_BLOCK_SIZE - sizeof(dw)) {
  *(uint32 *) cursor = dw;
  cursor += sizeof(dw);
 }
 return (*this);
}

DBOutStream &DBOutStream::operator <<(const char *str)
{
 uint16 len = strlen(str) + 1;
 if (cursor <= data + MAX_BLOCK_SIZE - sizeof(len) - len) {
  *this << len;
  memcpy(cursor, str, len);
  cursor += len;
 }
 return (*this);
}

DBOutStream &DBOutStream::operator <<(StrList &strList)
{
 uint16 n = 0;
 char *old = cursor;
 cursor += sizeof(n);
 
 StrList::iterator i;
 for (i = strList.begin(); i != strList.end(); i++) {
  operator <<(*i);
  n++;
 }
 char *p = cursor;
 cursor = old;
 operator <<(n);
 cursor = p;
 return (*this);
}

DBInStream &DBInStream::operator >>(uint8 &b)
{
 if (cursor <= data + datalen - sizeof(b))
  b = *cursor++;
 else
  b = 0;
 return (*this);
}

DBInStream &DBInStream::operator >>(uint16 &w)
{
 if (cursor <= data + datalen - sizeof(w)) {
  w = *(uint16 *) cursor;
  cursor += sizeof(w);
 } else
  w = 0;
 return (*this);
}

DBInStream &DBInStream::operator >>(uint32 &dw)
{
 if (cursor <= data + datalen - sizeof(dw)) {
  dw = *(uint32 *) cursor;
  cursor += sizeof(dw);
 } else
  dw = 0;
 return (*this);
}

DBInStream &DBInStream::operator >>(string &str)
{
 uint16 len;
 operator >>(len);

 if (cursor <= data + datalen - len && !cursor[len - 1]) {
  str = cursor;
  cursor += len;
 } else
  str = "";
 return (*this);
}

DBInStream &DBInStream::operator >>(StrList &strList)
{
 uint16 num;
 operator >>(num);
 int n = (int) num;

 strList.clear();
 while (n-- > 0) {
  string s;
  operator >>(s);
  strList.push_back(s);
 }
 return (*this);
}

添加CPerson類：
CPerson.h:
// Person.h: interface for the CPerson class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_PERSON_H__D259A8B7_7ACB_4624_8C9E_394B11FFA5C9__INCLUDED_)
#define AFX_PERSON_H__D259A8B7_7ACB_4624_8C9E_394B11FFA5C9__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "icqdb.h"

class CPerson: public DBSerialize
{
public:
 CPerson();
 virtual ~CPerson();
public:
 string Name;
 uint16 age;
 string Describe;
 void save(DBOutStream &out);
 void load(DBInStream &in);
};
#endif // !defined(AFX_PERSON_H__D259A8B7_7ACB_4624_8C9E_394B11FFA5C9__INCLUDED_)

Person.cpp:
// Person.cpp: implementation of the CPerson class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "TestBerkeleyDB.h"
#include "Person.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CPerson::CPerson()
{

}

CPerson::~CPerson()
{

}
void CPerson::save(DBOutStream &out)
{
 out << Name << age << Describe;
}

void CPerson::load(DBInStream &in)
{
 in >> Name >> age >> Describe;
}