PHP MySQL expects mysqli boolean given

Question

I have a php script that changes a database when the page is requested. Here is the php:

Answer 1

That error occurs because $con is not being correctly initialized (probably because, as many servers do, MySQL is restricted to local connections only). That's why you get the error after mysqli_connect().

If you can't connect to MySQL, you should kill the script or show an error message, without trying to query an empty object.

One alternative:

if (!$con) {
    echo "Error connecting to MySQL: " . mysql_connect_error();
    die; // You can kill the script here
}

Another one:

if (!$con) { // Error connecting
    echo "Error connecting to Mysql: " . mysql_connect_error();
    // Another message here if you want
}
else { // Connection ok
    mysqli_query( /* bla bla bla */ );
    // ...
}

Note that I'm verifying the $con value (if null or not) instead of mysqli_connection_errno(), because it won't return a value if the connection variable is not well defined.

This kind of verification is taken directly from mysqli_connect() documentation examples.