char query[300];
sprintf(query,"insert into  chenlan(NO) values (%d);",i); i是一个循环变量，从1到19，chenlan是我在mysql数据库中创建的一个表，NO是int，执行完以后，只能插入1，底下的就进行不了了，请各位高手帮帮忙，谢谢先。
开发环境VC6.0

long lCount = pMessages->Count - 1;
  // 遍历每封信
  FILE *fp;
  FILE *fp1;
   FILE *fp2;

     for(long i = 1; i <= lCount; i++)
     {  
    // char *a = 0;
     _bstr_t   a = pPOP3->GetMessageUID(i);
     int alen = strlen(a);

     pMessage = pMessages->Item[i];
 
     custom1.bstrSubject = pMessage->Subject;
     custom1.bstrFrom= pMessage->From;
     custom1.bstrBody = pMessage->Body;

  
    if ((fp1 = fopen("d:\\topgun.txt", "r")) == NULL)
             {
                exit(0);         
             }
             fseek(fp1,1L*33*(i-1),SEEK_SET);//每输出一次，将从后30个字节开始读并与这次的比较
             fread(DiskID, 30, 1, fp1);
             fclose(fp1);
 
     if(strcmp(a,DiskID)!=0)//DiskID和a比较
     {
           printf("(%d)Subject:%s, From:%s, Body:%s\r\n", i, (const char*)custom1.bstrSubject , (const char*)custom1.bstrFrom, (const char*)custom1.bstrBody); pMessage.Release();
     }
    else
    {
            printf("%s\r\n","No New Email!");
        
    }
  

    if ((fp = fopen("d:\\topgun.txt", "r+")) == NULL)//以追加的方式的写入文件
    {
      exit(0);         
    }
    fseek(fp,1L*33*(i-1),SEEK_SET);
    fwrite((const char*)a, alen, 1, fp);
    fwrite("\r\n", sizeof(" "), 1, fp);//换行
    fclose(fp);


  // str.Format("insert into topgun (num) values (%d)", i);
   
    sprintf(query,"insert into  chenlan(NO) values (%d);",i);//格式化的数据写入某个字符串
    //sprintf(query,"insert into  chenlan (NO) values ("&i&")");
                                                                  
    if(mysql_query(&mysql,query)!=0) //执行插入语句
         {

            printf("insert data error");   
         
         }
         else
         {
              printf("insert data success");
         }         
     mysql_close(&mysql);