Incorrect encoding of the Cyrillic's characters by BindValue - sql-server

Question

I have DB on MS SQL 2008 R2
I install follow software:
Ubuntu 16
Apache 2
PHP 7
Symfony 3.0 (with leaseweb/doctrine-pdo-dblib)
Windows Server 2008 R2 SP1
MS SQL Server 2008 R2 SP3 (with Cyrillic_General_CI_AS - I can't change the collation)
In my project, there is controller which has follow code
$em = $this->getDoctrine()->getManager();
$connection = $em->getConnection();
$sql="
select
isnull(ID,'') as 'id'
,isnull(SNAME,'') as 'sname'
,isnull(FNAME,'') as 'fname'
from TBL1
where SNAMElike '%'+:sname+'%' ";
$sql = iconv('UTF-8','Windows-1251', $sql);
$statement = $connection->prepare($sql);
$statement->bindValue(':sname', iconv('UTF-8', 'Windows-1251', $request->request->get('sname')), 'text');
$statement->execute();
In SQL Server Profiler I watch the string 0xc8e2e0edeee2 instead of Агеев. As you can see the codes is come from UTF8.
if I don't use the code page conversion,
$statement->bindValue(':sname', $request->request->get('sname'), 'text');
I see the string 0xd098d0b2d0b0d0bdd0bed0b2 in SQL Server Profiler.
If I don't use BindValue and put the variable into SQL like it's shown below
$sname = $request->request->get('sname');
$em = $this->getDoctrine()->getManager();
$connection = $em->getConnection();
$sql="
select
isnull(ID,'') as 'id'
,isnull(SNAME,'') as 'sname'
,isnull(FNAME,'') as 'fname'
from TBL1
where SNAMElike '%'+'".$sname."'+'%' ";
$sql = iconv('UTF-8','Windows-1251', $sql);
$statement = $connection->prepare($sql);
$statement->execute();
I watch correct string Иванов in SQL Server Profiler.
If the variable containts a string which has only latin charasters then there areb't any problem.
I send the string Ivanov and I watch the string Ivanov.
What is the problem?

Answer 1

The problem is in quoter function that called for each string parameter dblib_handle_quoter in ext\pdo_dblib\dblib_driver.c. It will convert any string containing character with codes outside of 32 > char > 127 range into binary string.
So if Агеев is not converted to 'Windows-1251' it becomes 0xd098d0b2d0b0d0bdd0bed0b2 - a UTF-8 representation converted to binary string (something like Рванов).
SQL Server then implicitly converts this binary value to string using:
single-byte conversion (with CP1251 code page in your case i guess), if expected data type is char or varchar. Here you need to convert parameters to Windows-1251.
unicode conversion, if expected data type is nchar or nvarchar. Here you need to convert parameters to UCS-2LE.
That's why there is no other choice (at least for now) than to use iconv for parameters.
PS If you set connection charset right, you shouldn't need to convert $sql as it should be done by dblib.
I use freetds-1.00.13 with PHP7 as pdo-dblib like this (data types is varchar):
function pdo_params(...$params){
foreach ($params as &$v){
$v = iconv('UTF-8','Windows-1251', $v);
}
unset($v);
return $params;
}
$dsn = 'dblib:dbname=DataBase;host=sql.server.host.name';
<...>
$dbh = new PDO($dsn, $user, $password,array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION));
$stmt = $dbh->prepare('INSERT INTO table (a,b) VALUES (?,?)');
$stmt->execute(pdo_params("Test",$msg));