文件读写有关问题

文件读写问题
我声明了 unsigned char buf[20480]，在程序中给buf赋值了，想把它插入到数据库的table表中，表中字段的类型是image，该怎么写呢？
我的思路是：把值写入到二进制的文件中，再保存到数据库，但我不知道该怎么写？ 哪位大侠知道呢？ 
或者有更好的方法吧buf的值插入到image类型的字段中


[解决办法]

C/C++ code

SQL Server2000 我用的image 类型 //存储 TBlobField *blob_pic=(TBlobField *)UserMod->TInsert->FieldByName("IMAGE");     try     {         blob_pic->LoadFromFile(app_path+"\\temp\\temp.jpg");     }     catch(...)     {       ShowMessage("图像存盘失败！");     }     UserMod->TInsert->Post();     UserMod->TInsert->Refresh();   } //读取 TBlobField *blob_pic=(TBlobField *)DBGrid4->DataSource->DataSet->FieldByName("IMAGE");     try     {         blob_pic->SaveToFile(app_path+"\\temp\\temp1.jpg");         Image9->Picture->LoadFromFile(app_path+"\\temp\\temp1.jpg");     }     catch(...)     {         ShowMessage("图像读取失败！");     }     delete blob_pic;//--------struct数据存取---------------------------------------//结构体定义：typedef struct    {        unsigned short Weight;        unsigned short  Dis;        char  Type;        char  Speed;    }VehAxle;VehAxle  Axle[15],PrintAxle[15];//---------------------------------//数据写入 C/C++ code     TBlobField *BlobField=(TBlobField *) DataMod->InsertTable->FieldByName("Veh_Detail");        //BlobField->AsString=*sp;        //delete sp;        FILE *fp = fopen("save.dat","wb");        fwrite(&Axle,sizeof(VehAxle)*15,1,fp);        //fread(&Axle,sizeof(VehAxle)*15,8,fp);        fclose(fp);        try        {            BlobField->LoadFromFile("save.dat");        }        catch(...)        {        }//数据读取C/C++ code    TBlobField *blob_file=(TBlobField *)Veh_DBGrid->DataSource->DataSet->FieldByName("Veh_Detail");   try   {    blob_file->SaveToFile("read.dat");    Sleep(10);    FILE *fp=fopen("read.dat","r+b");    fread(&PrintAxle,sizeof(VehAxle)*15,1,fp);    fclose(fp);   }   catch(...)   {       //   }本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/xjq2003/archive/2009/02/17/3898634.aspx
[解决办法]
我以前做过图片存取，用SQL 2000，在数据里，图片是以二进制形式存的。那时遇到一个问题，就没办法插入单个数据。只能，删除原有的行，重新插入这个行，插入同时把图片一起存进去。单个插入图片，不行。
[解决办法]
SQL SERVER 2000数据库
表TABLE1 字段imageid int型，image image型，自增字段

BCB6.0 TADOConnection，TADOQuery

//读写imageid=1记录的image字段数据
C/C++ code
//---------------------------------------#include <vcl.h>#pragma hdrstop#include "Unit1.h"//---------------------------------------#pragma package(smart_init)#pragma resource "*.dfm"TForm1 *Form1;unsigned char buf[20480];//---------------------------------------__fastcall TForm1::TForm1(TComponent* Owner)        : TForm(Owner){}//---------------------------------------void __fastcall TForm1::Button1Click(TObject *Sender){         //填充buf...         ...         //写入image字段          ADOQuery1->Close();         ADOQuery1->SQL->Text="SELECT image FROM TABLE1 WHERE imageid=1";         ADOQuery1->Open();         ADOQuery1->Edit();         TMemoryStream *S=new TMemoryStream;         S->SetSize(20480);         S->Clear();         S->Position=0;         S->Write(buf,20480);         TBlobField *T=(TBlobField*)(ADOQuery1->FieldByName("image"));         T->Clear();         T->LoadFromStream(S);         ADOQuery1->Post();         ADOQuery1->Close();         delete S;}//---------------------------------------void __fastcall TForm1::Button2Click(TObject *Sender){         ZeroMemory(buf,sizeof(buf));//清零          //读取image字段          ADOQuery1->Close();         ADOQuery1->SQL->Text="SELECT image FROM TABLE1 WHERE imageid=1";         ADOQuery1->Open();         TMemoryStream *S=new TMemoryStream;         S->SetSize(20480);         S->Clear();         S->Position=0;         TBlobField *T=(TBlobField*)(ADOQuery1->FieldByName("image"));         T->SaveToStream(S);         S->Position=0;         S->Read(buf,20480);//填充buf         ADOQuery1->Close();         delete S;}//---------------------------------------