odbc_binmode

(PHP 4, PHP 5, PHP 7)

odbc_binmode — Handling of binary column data

说明

bool odbc_binmode ( resource $result_id , int $mode )

Enables handling of binary column data. ODBC SQL types affected are BINARY, VARBINARY, and LONGVARBINARY.

When binary SQL data is converted to character C data, each byte (8 bits) of source data is represented as two ASCII characters. These characters are the ASCII character representation of the number in its hexadecimal form. For example, a binary 00000001 is converted to "01" and a binary 11111111 is converted to "FF".

LONGVARBINARY handling
binmode longreadlen result
ODBC_BINMODE_PASSTHRU 0 passthru
ODBC_BINMODE_RETURN 0 passthru
ODBC_BINMODE_CONVERT 0 passthru
ODBC_BINMODE_PASSTHRU 0 passthru
ODBC_BINMODE_PASSTHRU >0 passthru
ODBC_BINMODE_RETURN >0 return as is
ODBC_BINMODE_CONVERT >0 return as char

If odbc_fetch_into() is used, passthru means that an empty string is returned for these columns.

参数

result_id

The result identifier.

If result_id is 0, the settings apply as default for new results.

Note: Default for longreadlen is 4096 and mode defaults to ODBC_BINMODE_RETURN. Handling of binary long columns is also affected by odbc_longreadlen().

mode

Possible values for mode are:

  • ODBC_BINMODE_PASSTHRU: Passthru BINARY data
  • ODBC_BINMODE_RETURN: Return as is
  • ODBC_BINMODE_CONVERT: Convert to char and return

返回值

成功时返回 TRUE， 或者在失败时返回 FALSE。

User Contributed Notes

yhalmoe at yahoo dot no 14-Dec-2009 05:45
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.
bortuzar 12-Feb-2009 04:28
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); ?>
mizmerize at yahoo dot com 11-Jan-2006 03:59
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...
andrea dot galli at acotel dot com 28-Apr-2003 05:27
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;

?>