How to disable WordPress trackbacks?

I have high Google Page Rank, and as a result of that, lots of spammers make trackbacks. Every day I have to delete them.

Will those trackbacks negatively affect my site’s SEO? How can I disable all trackbacks on my site?

I have run the following code in my MySQL admin and using the WordPress Manage DB plugin, but it shows me an error.

UPDATE wp_posts SET ping_status="closed" WHERE post_status="publish" AND post_type="post";

UPDATE wp_posts SET ping_status="closed" WHERE post_status="publish" AND post_type="page";

This can be solved using the Bulk Edit WordPress functionality.

and

Change the number of items to be shown in Screen Options, so you can select all posts/pages at once.

Two things worth noting in the Q&A pointed by @BartKarp:

• There is the option to turn off trackbacks/pingbacks under Settings > Discussion.

• it has a link to a plugin by @chrisguitarguy. If you want to implement total blockage of trackbacks, use chris’.