php / mysql选择id = url id的位置

I have a problem with my script. I have a project page and if you click on one of your project (this is a list of the projects of the user) you go to the project page with project.php?project=id.

The project scipt:

                <?php
            require_once 'core/init.php';
            include("header.php");

            ?>

            <?php
            $project = DB::getInstance()->query("SELECT * FROM projects WHERE user_id = '" . $_SESSION['user'] . "' ");
            $project_item = new Projectitem();

            if(!$project->count()) {
                echo 'No Projects';
            } else {

                ?>
                <div class="table-responsive">
                <table class="table table-bordered">
                <?php
                foreach($project->results() as $project) {

                echo "<tr>";?>
                <td width="9,375em"><img src="<?php echo $project->project_img; ?>"><?php
                echo "</td>";
                echo "<td>";?>   


                <a href="project_item.php?project=<?php echo escape($project->id); ?>"><?php echo escape($project->name); ?></a>

                <?php
                echo "</td>";
                echo"</tr>";
                }
            }

            echo "</table>";
            echo "</div>";

            include("footer.php");
            ?>

If you click as exmplain on a project with id 3 you will get the next result:

project_item.php?project=3

The project page script:

            <?php
        require_once 'core/init.php';
        include("header.php");

        ?>

        <?php
        $project = DB::getInstance()->query("SELECT * FROM projects  WHERE id = ? ");

        if(!$project->count()) {
            echo 'No Projects';
        } else {

            ?>
            <div class="table-responsive">
            <table class="table table-bordered">
            <?php
            foreach($project->results() as $project) {

            echo "<tr>";?>
            <?php echo "<td>";?>   


            <?php echo escape($project->name); ?>

            <?php
            echo "</td>";
            echo"</tr>";
            }
        }

        echo "</table>";
        echo "</div>";

        include("footer.php");
        ?>

How can i get the right project with the query?

SELECT * FROM projects  WHERE id = ? //(the id from the url)