PHP PDO & Large Objects (LOB) broken after update - php

Question

A few months ago, my Ubuntu package auto-updated PHP from 7.0.8 to 7.0.13, at which point my script for updating photos stored on a SQL database started failing. I got around this by reinstalling 7.0.8. Last month, I was again auto-updated to 7.0.15 and my script failed again.
My script writes a jpg image to a MS-SQL database, using PDO & FreeTDS, plus Large Objects (LOB) to handle the photo. I emphasise that it worked up to PHP version 7.0.8. The following is a test script isolating my problem.
<?php
$dsn = 'dblib:dbname=photos;host=gary';
$id = 693925;
$dbh = new PDO($dsn, $user, $password);
$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
try {
$photo = file_get_contents("coco.jpg");
$query = "UPDATE photo_table SET photo = :photo WHERE id = :id";
$stmt = $dbh->prepare($query);
$stmt->bindValue(":photo", $photo, PDO::PARAM_LOB);
$stmt->bindValue(":id", $id, PDO::PARAM_INT);
$stmt->execute();
}
}
catch (PDOException $e) {
echo $e->getMessage();
}
The result is an "Incorrect syntax" error!?
SQLSTATE[HY000]: General error:
102 Incorrect syntax near '����'.[102] (severity 15) [(null)]
Using the latest available PHP version 7.0.15, reading from the database works, including reading the photo as a Large Object. There is no problem writing every other field to the database, it only fails on my image.
Despite searching over the last few weeks, I still have to find someone else reporting the same problem.
I am after any advice, either a change to the code, or some configuration settings to allow LOBs to work again.

Answer 1

I suggest you use bindParam instead of bindValue always because in bindParam
Unlike PDOStatement::bindValue(), the variable is bound as a
reference and will only be evaluated at the time that
PDOStatement::execute() is called.
$photo = file_get_contents("coco.jpg");//change this to below
$photo = fopen($_FILES['file']['tmp_name'], 'rb');
$query = "UPDATE photo_table SET photo = :photo WHERE id = :id";
$stmt = $dbh->prepare($query);
$stmt->bindValue(":photo", $photo, PDO::PARAM_LOB);//change to this below
$stmt->bindParam(":photo", $photo, PDO::PARAM_LOB);
$stmt->bindValue(":id", $id, PDO::PARAM_INT);//change this to below
$stmt->bindParam(":id", $id, PDO::PARAM_INT);
This is just only suggestions check here...... http://php.net/manual/en/pdo.lobs.php & http://www.php.net/manual/en/pdostatement.bindparam.php#refsect1-pdostatement.bindparam-description

Answer 2

My solution/workaround was to convert the binary from the image into hexadecimal representation before sending the data to SQL.
$photo = bin2hex(file_get_contents("coco.jpg"));
converting it back again during the SQL statement.
$query =
"UPDATE photo_table SET photo=CONVERT(varbinary(max), :photo, 2) WHERE id = :id";