Why does this SQL UPDATE query not work with a variable for WHERE?

Question

this is my first post here at Stack Overflow. I know the question has been asked many times before. I went through many answers, tried all of them (except the correct approa

Answer 1

Column Names are not givn in query

UPDATE table_name SET column_name1 = expr1, column_name2 = expr2, ... [WHERE condition];

So, your query will be something like this and check column names in database:

$sql =  "UPDATE VideoArchiv             
                SET titel='".$_POST["titel"]."',schauspieler='".$_POST["schauspieler"]."'
                WHERE id=$id";

Note: This is sql vulnerable, so please add mysql real escape function (https://www.php.net/manual/en/function.mysql-real-escape-string.php) or convert it to pdo.