Title: WordPress search causing database error Last modified: February 8, 2021 --- # WordPress search causing database error * Resolved [kcmau](https://wordpress.org/support/users/kcmau/) * (@kcmau) * [5 years, 4 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/) * Hide Posts seems to be breaking the WordPress search and throwing a database error. - WordPress 5.6.1 - WordPress Hide Posts 0.5.3 - PHP 7.4.9 - MySQL 5.7.33 * A search for “help me” produces: * ``` WordPress database error: [Not unique table/alias: 'wp_postmeta'] SELECT SQL_CALC_FOUND_ROWS DISTINCT wp_posts.ID FROM wp_posts LEFT JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id AND wp_postmeta.meta_key = '_whp_hide_on_search' ) LEFT JOIN wp_postmeta ON wp_posts.ID = wp_postmeta.post_id WHERE 1=1 AND (((wp_posts.post_title LIKE '%help me%') OR (wp_postmeta.meta_value LIKE '%help me%') OR (wp_posts.post_excerpt LIKE '%help me%') OR (wp_posts.post_content LIKE '%help me%'))) AND (wp_posts.post_password = '') AND ( wp_postmeta.post_id IS NULL ) AND wp_posts.post_type IN ('post', 'page', 'attachment') AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID ORDER BY wp_posts.post_title LIKE '%help me%' DESC, wp_posts.post_date DESC LIMIT 0, 12 ``` * _(formatted this to make it a little more readable)_ * I can see the query has two left joins to the same table wp_postmeta without the use of table aliases, so MySQL is a little unhappy. * I’ve tried deactivating all other plugins and get the same result. I’ve also tried deactivating WordPress Hide Posts and my search results are returned correctly. * I only have the plugin enabled in my private Dev site at the moment, I can afford to have search not working in Prod but the same problem was occurring there as well. * Any suggestions what to try next? Any help appreciated! * Thanks Viewing 4 replies - 1 through 4 (of 4 total) * Plugin Author [MartinCV](https://wordpress.org/support/users/martin7ba/) * (@martin7ba) * [5 years, 4 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/#post-14025352) * Hello, * Thank you for reporting this. * I will review this tonight and get back to you. * Which theme do you use? Have you tried with another theme? * Best, Martin * Thread Starter [kcmau](https://wordpress.org/support/users/kcmau/) * (@kcmau) * [5 years, 4 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/#post-14028069) * Hi Martin, * It’s a custom theme we had made and updated over the years. * Ok, I just tried TwentyTwenty and it disappears. It has to be something in our theme that is clashing with WHP right? * Doh, why didn’t I think to try another theme first! * I’ll leave the thread open for now and report back what I find. * Thank you! You have been most helpful. * Regards, Pete * Thread Starter [kcmau](https://wordpress.org/support/users/kcmau/) * (@kcmau) * [5 years, 4 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/#post-14028605) * Hi Martin, * I’ve found the issue! We are using the [Advanced Custom Fields](https://www.advancedcustomfields.com/) plugin and I’ve found the code from [Adam Balée](https://adambalee.com/search-wordpress-by-custom-fields-without-a-plugin/) in our theme’s function.php file that enables searching of custom fields without the need for another plugin. * I’ve fixed it using a table alias for the postmeta table in Adam’s code. Here’s the modified code: * ``` function cf_search_join( $join ) { global $wpdb; if ( is_search() ) { $join .=' LEFT JOIN '.$wpdb->postmeta. ' pm ON '. $wpdb->posts . '.ID = pm.post_id '; } return $join; } add_filter('posts_join', 'cf_search_join' ); function cf_search_where( $where ) { global $pagenow, $wpdb; if ( is_search() ) { $where = preg_replace( "/\(\s*".$wpdb->posts.".post_title\s+LIKE\s*(\'[^\']+\')\s*\)/", "(".$wpdb->posts.".post_title LIKE $1) OR (pm.meta_value LIKE $1)", $where ); } return $where; } add_filter( 'posts_where', 'cf_search_where' ); ``` * Of course the _cf\_search\_distinct_ function does not need any changes as it does not contain any references postmeta. * This gives me the advanced search capability and WHP is still functioning as expected regular posts and custom post types. * It maybe worth considering using table a table alias for postmeta in WHP to avoid any potential conflicts? I imagine we wouldn’t be the only ones using this code. * I hope this helps someone who may be having a similar issue. * Thanks again for setting me on the right path. * Kind Regards, Pete * Plugin Author [MartinCV](https://wordpress.org/support/users/martin7ba/) * (@martin7ba) * [5 years, 2 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/#post-14178931) * Hi, sorry for super late response and I am glad you found a solution. * I have been rather busy on personal matter this past month, but I will review this code and see what updates can be done. * I will be releasing major update soon, so I might include this too. * Best, Martin Viewing 4 replies - 1 through 4 (of 4 total) The topic ‘WordPress search causing database error’ is closed to new replies. * ![](https://ps.w.org/whp-hide-posts/assets/icon-256x256.png?rev=2674332) * [Hide Posts](https://wordpress.org/plugins/whp-hide-posts/) * [Frequently Asked Questions](https://wordpress.org/plugins/whp-hide-posts/#faq) * [Support Threads](https://wordpress.org/support/plugin/whp-hide-posts/) * [Active Topics](https://wordpress.org/support/plugin/whp-hide-posts/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/whp-hide-posts/unresolved/) * [Reviews](https://wordpress.org/support/plugin/whp-hide-posts/reviews/) * 4 replies * 2 participants * Last reply from: [MartinCV](https://wordpress.org/support/users/martin7ba/) * Last activity: [5 years, 2 months ago](https://wordpress.org/support/topic/wordpress-search-causing-database-error/#post-14178931) * Status: resolved