PHP 上传/下载存储在数据库中的imge类型数据（图片）

//上传扫描件（图片以img数据类型存入数据中）
function mod_addPhoto()
{
    global $row_User;    
    global $mssql_connection;    
    if ($_FILES['myfile']['error'] > 0) {
            $back = array(            
            'message' => 'error',            
            'date' => '文件错误'        
            );        
            echo json_encode($back);        
            exit();    
            } else {        
            //判断是否选择了要上传的表格        
            if (empty($_POST['upfile'])) {
                       $back = array(                
                       'message' => 'error',                
                       'date' => '上传文件不能为空'            
                       );            
                       echo json_encode($back);            
                       exit();        
                       }        
                       //获取表格的大小，限制上传表格的大小5        
                       $file_size = $_FILES['myfile']['size'];        
                       if ($file_size > 100 * 1024 * 1024) {
                                   $back = array(                
                                   'message' => 'error',                
                                   'date' => '文件大小不能超过5M'            
                                   );            
                                   echo json_encode($back);            
                                   exit();        
                                   }        
                                   //获取文件参数        
                                   $imgfile = $_FILES['myfile'];        
                                   $name = $imgfile['name'];   //取得图片名称        
                                   $type = $imgfile['type']; //取得图片类型        
                                   $size = $imgfile['size'];  //取得图片长度       
                                    $tmpfile = $imgfile['tmp_name'];  //图片上传上来到临时文件的路径        
                                    $file = fopen($tmpfile, 'rb');        
                                    $content = fread($file, $size);        
                                    $content = "0x" . bin2hex($content);        
                                    fclose($file);        
                                    //限制上传表格类型        
                                    $file_type = $_FILES['myfile']['type'];        
                                    $file_type=substr($file_type, 6);        
                                    //获取当前时间        
                                    date_default_timezone_set('PRC');        
                                    $now_time = date('Y-m-d H:i:s', time());        
                                    //保存到数据库        
                                    $OAV_ID = $_GET['OAV_ID'];        
                                    $OVA_ID = create_ID("OA_VehicleAttach");       
                                     global $mssql_connection;        
                                     if (!$mssql_connection) {            
                                     $mssql_connection = open_mssqlconn();        
                                   }        
                                   $sfu_id = $row_User['SFU_ID'];        
                                   $sql1 = "INSERT INTO OA_VehicleAttach (OAV_ID, OVA_ID,OVA_Name, OVA_Date, OVA_Type, OVA_Size, OVA_Data, OVA_User)
                                    VALUES ('$OAV_ID', '$OVA_ID', '$name','$now_time','$file_type',$file_size, $content,'$sfu_id' )";        
                                    $sql = iconv("utf-8", "gbk", $sql1);   
                                    //PHP使用UTF-8编码。SQL Server 2008使用默认的GBK编码  在执行查询语句之前将查询语句及所要插入的数据转化为GBK编码。        
                                    $cursor = sqlsrv_query($mssql_connection, $sql);        
                                    $aa = sqlsrv_rows_affected($cursor);        
                                    if ($aa) {            
                                    $back = array(                
                                    'message' => 'success',               
                                     'date' => '文件上传成功'            
                                     );            
                                     echo json_encode($back);            
                                     exit();        
                                     } else {           
                                     $back = array(              
                                     'message' => 'fail',               
                                     'date' => '文件上传失败'            
                                     );            
                                     echo json_encode($back);            
                                     exit();        
                                     }    
                                     }
                                     }




//下载扫描件
function  mod_down_scanning_copy()
{
    $id = $_GET['OVA_ID'];    
    //$id = getGP('OAV_ID', 'G');    
    $sql = "SELECT OVA_ID,OAV_ID,OVA_Name,OVA_Data,OVA_User,OVA_Size FROM OA_VehicleAttach where OVA_ID='" . $id . "'";    
    $cursor = mssqlquery($sql);    
    $row = sqlsrv_fetch_array($cursor, SQLSRV_FETCH_ASSOC);    
    if(isset($row['OVA_Name'])){       
     $filename=$row['OVA_Name'];        
     $filedata=$row['OVA_Data'];        
     $filesize=$row['OVA_Size'];    
     }   
     // $binaryStr = base64_decode($filedata); 
     //   file_put_contents($filename, $binaryStr);    
     $filePath = 'download/' . $filename;    
     $file = fopen($filePath, "w");//打开文件准备写入    
     fwrite($file, $filedata);//写入    
     fclose($file);//关闭
     //    header("content-disposition:attachment;filename=".$filename);
     //    header("content-length:".$filesize);
     //    readfile($filedata);    
     if(file_exists($filePath)){        
     header("Content-type:application/octet-stream");        
     header("Content-Disposition:attachment;filename = ".$filename);        
     header("Accept-ranges:bytes");        
     header("Content-length:".$filesize);        
     readfile($filePath);    
     }
}
//SQL查询
function mssqlquery($Q)
{
    global $mssql_connection;    
    if (!$mssql_connection) {        
    $mssql_connection = open_mssqlconn();   
     }    
     $Q = iconv("utf-8", "gbk", $Q);    
     $cursor = sqlsrv_query($mssql_connection, $Q);    
     if (!$cursor) {        
     echo "SQL查询出错.\n";        
     die(print_r(sqlsrv_errors(), true));    
     }    
     return $cursor;
     }
//获取数据库连接
$mssql_connection = '';
function open_mssqlconn()
{
    global $mssql_connection;
    //    global $MSSQL_SERVER;
    //    global $connectionInfo;    
    $MSSQL_SERVER = "DESKTOP-CA04H1Q\SQLEXPRESS";    
    $connectionInfo = array("Database" => "ToncentHuaJie", "UID" => "用户名", "PWD" => "密码");    
    if (!$mssql_connection) {        
    $mssql_link = sqlsrv_connect($MSSQL_SERVER, $connectionInfo);
    //            sqlsrv_query("set NAMES GBK");        
    if (!$mssql_link) {            
    echo "Could not connect.\n";            
    die(print_r(sqlsrv_errors(), true));       
     }        
     return $mssql_link;    
     } else {        
     return $mssql_connection;    
     }
     }