Using WordPress ‘require_wp_db()’ PHP function

The require_wp_db WordPress PHP function loads the database class file and instantiates the $wpdb global.

Usage

require_wp_db();

Parameters

• None

More information

See WordPress Developer Resources: require_wp_db

Examples

Accessing the database to retrieve a list of post titles

// Load the database class
require_wp_db();

// Use the global $wpdb object
global $wpdb;

// Query to get post titles
$results = $wpdb->get_results("SELECT post_title FROM $wpdb->posts WHERE post_status = 'publish'");

// Loop through and display post titles
foreach ($results as $result) {
    echo $result->post_title . '<br>';
}

Inserting data into a custom table

// Load the database class
require_wp_db();

// Use the global $wpdb object
global $wpdb;

// Custom table name
$table_name = $wpdb->prefix . 'my_custom_table';

// Data to insert
$data = array(
    'name' => 'John Doe',
    'email' => '[email protected]'
);

// Insert data into the custom table
$wpdb->insert($table_name, $data);

Updating data in the wp_options table

// Load the database class
require_wp_db();

// Use the global $wpdb object
global $wpdb;

// Update the site name
$wpdb->update(
    $wpdb->options,
    array('option_value' => 'New Site Name'),
    array('option_name' => 'blogname')
);

Deleting rows from a custom table

// Load the database class
require_wp_db();

// Use the global $wpdb object
global $wpdb;

// Custom table name
$table_name = $wpdb->prefix . 'my_custom_table';

// Delete rows with email [email protected]
$wpdb->delete($table_name, array('email' => '[email protected]'));

Executing a custom SQL query

// Load the database class
require_wp_db();

// Use the global $wpdb object
global $wpdb;

// Custom SQL query
$sql = "ALTER TABLE {$wpdb->prefix}my_custom_table ADD COLUMN age INT(3) NOT NULL";

// Execute the custom SQL query
$wpdb->query($sql);