如何从数据库中检索以前的记录

I am writing a Custom Query in WordPress database to get the previous record from the posts table.

Example: I have an ID of 34975; after I query the database I should get the ID as 34972, which is the previous record ID.

SQL

$results = $wpdb->get_results( "SELECT * FROM agencies_posts WHERE ID = '34975 ' LIMIT 1", OBJECT );
foreach( $results as $item ){
    $previous_depature_port = $item->ID;
}

If I'm understanding your question correctly, you need to add ORDER BY and use < instead of =:

SELECT * 
FROM agencies_posts 
WHERE ID < 34975 
ORDER BY ID DESC 
LIMIT 1

Pretty sure you want:

select *
  from agencies_posts
 where id = (select max(id) from agencies_posts where id < '34975')

If the 'current' id is what's known and you just want the one prior.

Select everything with an id less than the one you are interested in, and only grab the first one

SELECT * 
FROM agencies_posts
WHERE ID < '34975 ' 
ORDER BY ID DESC LIMIT 1"