<?php
/*
Plugin Name: Simple Debug
Plugin URI: http://example.com/
Description: Append ?debug=1 to any URL to display debug information if you are an admin
*/
 
add_action( 'init', 'ssd_debug_check' );
 
function ssd_debug_check() {
    if( isset( $_GET['debug'] ) && current_user_can( 'manage_options' ) ) {
        if( !defined( 'SAVEQUERIES' ) )
            define( 'SAVEQUERIES', true );
        add_action( 'wp_footer', 'ssd_debug_output' );
    }
}
 
// Print debug information
function ssd_debug_output() {
    global $wpdb;
    echo "<pre>";
    print_r($wpdb->queries);
    echo "</pre>";
}

<?php
/*
Plugin Name: Unused Tags
Plugin URI: http://example.com/
Description: Find unused tags and rename or delete them
*/
 
// Add an entry for our option page to the Posts menu
add_action('admin_menu', 'ssd_utags_add_page');
function ssd_utags_add_page() {
    add_posts_page( 'Unused Tags', 'Unused Tags', 'manage_options',
        'ssd_utags', 'ssd_utags_option_page' );
}
 
// Catch any action parameter in query string
add_action( 'admin_init', 'ssd_utags_do_action' );
 
// Proceed to requested ssd_action if applicable
function ssd_utags_do_action() {
    if( !isset( $_REQUEST['ssd_action'] ) )
        return;
 
    if( !current_user_can( 'manage_options' ) )
        wp_die( 'Insufficient privileges!' );
 
    $id     = $_REQUEST['id'];
    $action = $_REQUEST['ssd_action'];
 
    if( $action == 'done' ) {
        add_action( 'admin_notices', 'ssd_utags_message' );
        return;
    }
 
    check_admin_referer( 'ssd_utags-'.$action.'_tag'.$id );
 
    switch( $action ) {
        case 'rename':
            $newtag = array( 'name' => $_POST['name'], 'slug' => $_POST['name'] );
            wp_update_term( $id, 'post_tag', $newtag );
            break;
        case 'delete':
            wp_delete_term( $id, 'post_tag' );
            break;
    }
 
    wp_redirect( add_query_arg( array( 'ssd_action' => 'done' ) ) );
 
}
 
// Admin notice
function ssd_utags_message() {
    echo "<div class='updated'><p>Action completed</p></div>";
}
 
// Draw the tag management page
function ssd_utags_option_page() {
    ?>
    <div class="wrap">
        <?php screen_icon(); ?>
        <h2>Unused Tags</h2>
 
        <?php
 
        if( $tags = ssd_utags_find_orphans() ):
 
        echo '<p>You currently have '.count( $tags ). ' unused tags:</p>';
        echo '<ol>';
 
        foreach( $tags as $tag ) {
            $id   = $tag->term_id;
            $name = esc_attr( $tag->name );
 
            $delete_url= add_query_arg( array('ssd_action'=>'delete','id'=>$id) );
            $nonced_url= wp_nonce_url( $delete_url, 'ssd_utags-delete_tag'.$id );
            ?>
            <li>
            <form action="" method="post">
            <?php wp_nonce_field( 'ssd_utags-rename_tag'.$id ); ?>
            <input type="hidden" name="ssd_action" value="rename" />
            <input type="hidden" name="id" value="<?php echo $id; ?>" />
            <input type="text" name="name" value="<?php echo $name; ?>" />
            <input type="submit" value="Rename" /> or
            <a href="<?php echo $nonced_url; ?>">delete</a> this tag
            </form>
            </li>
 
        <?php }
 
        else: ?>
        <p>You have no unused tags.</p>
 
        <?php endif; ?>
 
        </ol>
    </div>
    <?php
}
 
// Find unused tags, return them in an array
function ssd_utags_find_orphans() {
    global $wpdb;
 
    $sql = "SELECT terms.term_id, terms.name FROM {$wpdb->terms} terms
            INNER JOIN {$wpdb->term_taxonomy} taxo
            ON terms.term_id=taxo.term_id
            WHERE taxo.taxonomy = 'post_tag'
            AND taxo.count=0";
 
    return $wpdb->get_results( $sql );
}

function ssd_validate_date( $date ) {
    // first test: pattern matching
    if( !preg_match( '!\d{2}/\d{2}/\d{4}!', $date ) )
        return 'wrong pattern';
 
    // second test: is date valid?
    $timestamp = strtotime( $date );
    if( !$ t i m e s t a m p )
        return 'date invalid';
 
    // third test: is the date from the past?
    if( $timestamp <= time() )
        return 'past date';
 
    // So far, so good
    return true;
}
 
// Test it:
 
var_dump( ssd_validate_date( '12/12/99' ) );
// string(12) "wrong pattern"
 
var_dump( ssd_validate_date( '35/30/1980' ) );
// string(12) "date invalid"
 
var_dump( ssd_validate_date( '03/30/1980' ) );
// string(9) "past date"
 
var_dump( ssd_validate_date( '03/30/2020' ) );
// bool(true)

$values = array(
‘column1’ = > ‘some string’,
‘column2’ = > 43
);
$where = array(
‘ID’ = > 1
);
$formats_values = array( ‘%s’, ‘%d’ );
$formats_where = array( ‘%d’ );
$wpdb- > update( $wpdb- > custom, $values, $where, $formats_values, $formats_where );
 
$values = array(
‘column1’ = > ‘new string’,
‘column2’ = > 44
);
$formats_values = array( ‘%s’, ‘%d’ );
$wpdb- > insert( $wpdb- > custom, $values, $formats_values );
 
$sql = “SELECT COUNT(ID) FROM {$wpdb- > posts}
WHERE post_status = ‘publish’ AND post_type = ‘post’”;
$num_of_posts = $wpdb- > get_var( $sql );
 
$sql = “SELECT `user_email`, `user_url`
FROM $wpdb- > users
WHERE user_login = ‘admin’”;
$object = $wpdb- > get_row( $sql, OBJECT );
$array_a = $wpdb- > get_row( $sql, ARRAY_A );
 
$sql = “SELECT `user_email` FROM $wpdb- > users”;
$emails = $wpdb- > get_col( $sql );
 
$sql = “SELECT YEAR(post_date) AS `year`, count(ID) as posts
FROM $wpdb- > posts
WHERE post_type = ‘post’ AND post_status = ‘publish’
GROUP BY YEAR(post_date)
ORDER BY post_date DESC”;
$results = $wpdb- > get_results( $sql, ARRAY_A );
 
$sql = “SELECT YEAR(post_date) AS `year`, count(ID) as posts
FROM $wpdb- > posts
WHERE post_type = ‘post’ AND post_status = ‘publish’
GROUP BY YEAR(post_date)
ORDER BY post_date DESC”;
$results = $wpdb- > get_results( $sql, ARRAY_A );
foreach( $results as $sum ) {
$year = $sum[‘year’];
$count = $sum[‘posts’];
echo “ < p > Posts published in $year: $count < /p > ”;
}
 
$sql = “DELETE from wp_comments
WHERE comment_author_url
LIKE ‘%evil.example.com%’”;
$deleted = $wpdb- > query( $sql );
 
$sql = “UPDATE $wpdb- > posts
SET comment_status = ‘closed’
WHERE post_date < DATE_SUB( NOW(), INTERVAL 90 DAY )
AND post_status = ‘publish’”;
$wpdb- > query( $sql );