Question

I am scratching my empty head with this issue:

When I have my logging data as procedural, everything works fine. I require the file once and can proceed with my select queries. If the connection to the DB file is however written as OOP. I get the error that No database selected

====

<?php

        // SETTING VALUES AS CONSTANTS

        DEFINE('DB_USER', 'root');
        DEFINE('DB_PASSWORD', '');
        DEFINE('DB_HOST', 'localhost');
        DEFINE('DB_NAME', 'tra');

        // CONNECTING JUST TO THE SERVER
        $dbc = @mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);

        if (!$dbc)  // IF IT CAN'T CONNECT, ISSUE A MESSAGE
             {
                die('Could not connect: ' . mysql_error());
        }

        // CONNECTING NOW TO THE DB
        mysql_select_db("tra", $dbc);

    ?>

So that up there works fine. I have got that in a separate file, (out of the root path)

But if I try to do it OOP, then, the rest of the queries that are to work once I have the access to the DB won’t work. I sometimes get the query written as output, I mean as if not executing, just the plain text:

   $mysqli = new mysqli("localhost", "root", "");
            $mysqli->select_db("tra");

I have tried tons of varieties with the OOP version, first instantiating separately such as

$mysqli = new mysli();
$mysqli->connect("127.0.0.1", "root", "", "tra");

or also

$mysqli = new mysqli("localhost", "root", "");
$mysqli-> select_db("tra");

but none of the tries with OOP will work. I mean, I have the book on my lap, so I am writing it ad litteram. The issue must be elsewhere.

The PHP version is 5.3.8 about the latest one.

The sql query that follows after the connection and selection of the DB (which works if the connection file is procedural, as I say) is:

$sql ="SELECT FName
                              FROM work_assignment, developer
                              WHERE developer.country = '".$country."'
                              AND work_assignment.from_language = '".$from."'
                              AND work_assignment.into_language = '".$into."'
                              AND work_assignment.developer_id = developer.developer_id

                              ";

Any ideas as to why?

Thanks a lot

Answer 1

From your comment I surmise you’re mixing the mysql and mysqli extensions. They are two separate extensions with nothing in common, except that they both connect to MySQL. If you’re connecting to the database using a mysqli object, use that object to run your queries. mysql_query will have no active connection, because you did not establish one using a mysql function.