WordPress has been set up in such a way there aren’t really many times when you need to really dive into the database. Sometimes you may be building a custom plugin where it does make more sense to use a custom structure in the database but those circumstances can be rare. Where a query can come in handy would be if a change is needed on a large site.
Recently I worked on a project with 10,000+ posts. Thousands of those posts had a snippet of unneeded HTML placed in the editor. To go through each of those posts would have taken hours upon hours of work. This is where working in the database came in handy
MAKE. A. BACKUP.
Before doing any kind of database work you need to have a backup. There is always the chance your SQL could break and bring down an entire site. Not having a back up is a careless and pointless mistake.
Access the Database
Not all hosts but most will offer some way of accessing your database. The most common is through a phpMyAdmin interface but it will vary from host to host. Once you have found it and made a backup in your particular situation you will need to navigate to the location where you can make SQL statements.
update wp_posts set post_content =
replace(post_content,’Content to update’,’Updated content’);
Replace the content to update and updated content portions in the snippet above and that will quickly go through your database and update an instance of “Content to update” with “Updated content” in all of your posts.