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The problem is that whenever I input a big-ass text in the form of my php page and try to INSERT it through a SQL query into the database, it gives me an error like this:

"You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ' 'sample title', 'spent the long months of the rainy season shut up in a small room th' at line 1"

The query is this:

$sql = "INSERT INTO `d` (`user_id`, `title`, `message`) VALUES ($user_id, '$topic', '$message')";

The interesting thing is that it gives me no error when I manually insert the values and run the query in phpmyadmin.

ScottMcGready
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user1592534
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2 Answers2

2

I bet there are single quotes ( ' ) in the string. Escape $topic before using it in your INSERT.

Cranio
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1

Use prepared statements:

$db = new PDO(...);
$stmt = $db.prepare("INSERT INTO `d` (`user_id`, `title`, `message`) VALUES ($user_id, :topic, :message)");
// I'm assuming that title is a VARCHAR(50) and message is a VARCHAR(500)
$stmt->bindParam(":topic", $topic, PDO::PARAM_STR, 50);
$stmt->bindParam(":message", $topic, PDO::PARAM_STR, 500);
$stmt->execute();

This places the job of escaping / properly passing data squarely in the hands of the database engine - which is where it belongs. Avoid building SQL strings from user input wherever you can and you'll avoid many potential SQL injection attacks.

Sean Vieira
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