Hi there,

Just wanted to share an issue that I resolved which turned out to be a conflict with a Piklist filter.

I have a get_terms defined in my plugin code similar to the following. While troubleshooting, get_terms with any kind of meta_query parameters would trigger a database error. It should be noted that this code worked prior to the 9.9.9 update.

$terms = get_terms( array(
	'taxonomy' => 'my_taxonomy',
	'hide_empty' => false,
	'meta_query' => array(
		'relation' => 'OR',	
		array(
			'key' => 'my_term_meta',
			'compare' => 'NOT EXISTS',
		),
		array(
			'key' => 'my_term_meta',
			'value' => '1',
			'compare' => '!=',
		)
	)
));

And the error:

WordPress database error: [Not unique table/alias: ‘wp_termmeta’]

I traced the culprit to class-piklist-taxonomy.php ‘terms_clauses’ filter. I removed the filter right before executing get_terms and the error went away.

From cursory observation, it looks like the Piklist filter may not have been adding table aliases.

Hope this info is useful.
Mike