odbc_binmode

(PHP 4, PHP 5, PHP 7, PHP 8)

odbc_binmode — Gestione delle colonne di dati binari

Descrizione

odbc_binmode(resource $id_risultato, int $modalità): bool

(Tipi di campi ODBC SQL coinvolti: BINARY, VARBINARY, LONGVARBINARY)

ODBC_BINMODE_PASSTHRU: Restituzione del dato binario direttamente al client
ODBC_BINMODE_RETURN: restituisce il dato inalterato
ODBC_BINMODE_CONVERT: Conversione in char

Quando si esegue la conversione da dati binari SQL a dati di tipo char del C, ciascun byte ( 8 bits) dei dati sorgenti vengono rappresentati da 2 caratteri ASCII. Questi caratteri sono la rappresentazione ASCII dei numeri nella loro forma esadecimale. Ad esempio, il valore binario 00000001 è convertito in "01" e il valore binario 11111111 è convertito come "FF".

**Gestione del tipo LONGVARBINARY**
Modalità	Impostazione di longreadlen	Comportamento
ODBC_BINMODE_PASSTHRU	0	direttamente al client
ODBC_BINMODE_RETURN	0	direttamente al client
ODBC_BINMODE_CONVERT	0	direttamente al client
ODBC_BINMODE_PASSTHRU	0	passthru
ODBC_BINMODE_PASSTHRU	>0	direttamente al client
ODBC_BINMODE_RETURN	>0	restituito inalterato
ODBC_BINMODE_CONVERT	>0	restituito come char

Se viene utilizzata odbc_fetch_into(), nei casi in cui il dato viene inviato direttamente al client, quest'ultima restituisce una stringa vuota per le colonne binarie.

Se l'argomento id_risultato è valorizzato a 0, il settaggio viene applicato come default per i nuovi risultati.

Nota: I valori di default per longreadlen è 4096, mentre la modalità di default è ODBC_BINMODE_RETURN. La gestione delle colonne di campi long binary, è anche gestita dalla funzione odbc_longreadlen()

Found A Problem?

Learn How To Improve This Page • Submit a Pull Request • Report a Bug

＋add a note

User Contributed Notes 4 notes

down

yhalmoe at yahoo dot no ¶

15 years ago

For Sybase users (this probably applies to MS-SQL Server as well) who are using ODBC:



I was using the same code as mizmerize, but I was getting truncated data back from the server (at the 32kb mark) when selecting data with the image datatype. My Sybase server has a @@textsize property of 2Gb, which should be plenty. But apparently, the php ODBC driver resets this to 32Kb when a connection is made, and then sets it back to 2Gb after. The solution is to do a query:



<?php odbc_exec($connH, "set textsize 131072"); ?>



immediately before your main query, in mizmerize's code. That should override the default setting.

down

mizmerize at yahoo dot com ¶

18 years ago

I am currently using an SQL Server 2000 used as a datasource for ODBC access, Testing PHP scripts from an Apache 2 server running on Windows 2000.

I was trying to get an image from the database using ODBC but the output always flushes automatically while I was just getting the result using odbc_result() function.

With this code, the picture automatically prints to the browser as soon as I hit odbc_result() (probably a bug, but bug reports aren't that easy to do).

<?php
  $connH=odbc_pconnect("ImageDB","sa","",SQL_CUR_USE_IF_NEEDED) or die(odbc_errormsg());
    $result=odbc_exec($connH, "SELECT Emp_Image FROM tblEmployeePics WHERE Emp_Id=547");
    if ($result) {                            
        odbc_longreadlen($result, 131072);        
        odbc_binmode($result,ODBC_BINMODE_PASSTHRU);                            
//upon calling this, the output flushes out to the browser... made me scratch        
$m_FValue=odbc_result($result, 1);
}
?>

...after 48 hours of scratching I finally made a work around, but by using a function in the bin2hex() function documentation...

<?php
      function hex2bin($data){ 
       $len = strlen($data); 
       return pack("H" . $len, $data); 
    } 

    
    $connH=odbc_pconnect("ImageDB","sa","",SQL_CUR_USE_IF_NEEDED) or die(odbc_errormsg());
    $result=odbc_exec($connH, "SELECT Emp_Image FROM tblEmployeePics WHERE Emp_Id=547");
    if ($result) {                            
        odbc_longreadlen($result, 131072);        
        odbc_binmode($result,ODBC_BINMODE_CONVERT);                            
        $m_FValue=odbc_result($result, 1);
        $out=hex2bin($m_FValue);
    }
?>

The trick was to convert the output into hex by changing odbc_binmode to  ODBC_BINMODE_CONVERT and using a handy function to convert it back to binary in order to facilitate manipulation of its size, depth etc...

down

andrea dot galli at acotel dot com ¶

21 years ago

Example: retrieve image from database.

<?php

   $Link_ID = odbc_connect("DSN", "user", "pass"); 
   $Query_ID = odbc_exec($Link_ID, "SELECT picture FROM categories"); 

   // change to ODBC_BINMODE_CONVERT for comparison 

   odbc_binmode($Query_ID, ODBC_BINMODE_RETURN);

   $Images = odbc_result($Query_ID, 1);

   echo $Images;

?>

down

-1

bortuzar ¶

15 years ago

I set the odbc_longreadlen() at the beggining of my script so nText field types dont get truncated, like this:



<?php odbc_longreadlen (0, 1000000); ?>

＋add a note