Encoding SQL_Latin1_General_CP1_CI_AS into UTF-8

I’m generating a XML file with PHP using DomDocument and I need to handle asian characters. I’m pulling data from the MSSQL2008 server using the pdo_mssql driver and I apply utf8_encode() on the XML attribute values. Everything works fine as long as there’s no special characters.

The server is MS SQL Server 2008 SP3

The database, table and column collation are all SQL_Latin1_General_CP1_CI_AS

I’m using PHP 5.2.17

Here’s my PDO object:

$pdo = new PDO("mssql:host=MyServer,1433;dbname=MyDatabase", user123, password123);

My query is a basic SELECT.

I know storing special characters into SQL_Latin1_General_CP1_CI_AS columns isn’t great, but ideally it would be nice to make it work without changing it, because other non-PHP programs already use that column and it works fine. In SQL Server Management Studio I can see the asian characters correctly.

Considering all the details above, how should I process the data?

Answer

I found how to solve it, so hopefully this will be helpful to someone.

First, SQL_Latin1_General_CP1_CI_AS is a strange mix of CP-1252 and UTF-8. The basic characters are CP-1252, so this is why all I had to do was UTF-8 and everything worked. The asian and other UTF-8 characters are encoded on 2 bytes and the php pdo_mssql driver seems to hate varying length characters so it seems to do a CAST to varchar (instead of nvarchar) and then all the 2 byte characters become question marks (‘?’).

I fixed it by casting it to binary and then I rebuild the text with php:

SELECT CAST(MY_COLUMN AS VARBINARY(MAX)) FROM MY_TABLE;

In php:

//Binary to hexadecimal
$hex = bin2hex($bin);

//And then from hex to string
$str = "";
for ($i=0;$i<strlen($hex) -1;$i+=2)
{
    $str .= chr(hexdec($hex[$i].$hex[$i+1]));
}
//And then from UCS-2LE/SQL_Latin1_General_CP1_CI_AS (that's the column format in the DB) to UTF-8
$str = iconv('UCS-2LE', 'UTF-8', $str);