In PHP, WordPress provides a set of functions and APIs to perform CRUD (Create, Read, Update, Delete) operations on its database. These operations allow you to interact with WordPress database tables to manage posts, pages, custom post types, comments, and other elements of your WordPress site. Below, I'll explain the basic CRUD operations in WordPress using PHP code snippets.

Please note that performing CRUD operations directly on the WordPress database is not always recommended, as it bypasses WordPress's built-in functionalities and can lead to potential issues if not done correctly. Instead, you should often use WordPress core functions and classes to handle these operations, as they ensure data integrity and proper handling of actions and filters.

1. Create (Insert) Operation: To create a new post or any other content type, use the wp_insert_post() function:

2. Read (Retrieve) Operation: To retrieve posts or any other content type, use the WP_Query class or relevant functions like get_posts() or get_pages():

3. Update Operation: To update an existing post or any other content type, use the wp_update_post() function:

4. Delete Operation: To delete a post or any other content type, use the wp_delete_post() function:

Again, remember to use these CRUD operations judiciously and prefer WordPress’s built-in functions whenever possible to ensure compatibility and proper handling of data. Directly manipulating the database should be done with caution.