Reputation: 43
I have a plethora of duplicate comments in my Wordpress database, specifically table wp_comments. Of course, those comments have a different IDs. I'd now like to de-dupe those comments based on the field comment_date which would identify all comments posted on the same date and time. I don't care which one of the duplicates remain.
What SQL query do I have to use to achieve this?
Thanks!
EDIT: I don't want to delete a specific comment date across the table, instead I want the database to scan for duplicate dates and remain with only one entry.
Upvotes: 1
Views: 797
Reputation: 13
The current top/accepted answer deletes all duplicate comments; however it runs into trouble where the comment_content contains strings that require escaping. E.g., "I'm so happy" entered as a comment twice -- won't be deleted because the comment content
comparison ends early due to the '
in the comment body. $wpdb->_real_escape
(docs) helped.
Fiddled with the accepted answer, and came up with the following. This was for a WP Multisite, also, so it loops through all of the multisite children as well. You can cut out the bit in the first $blog_ids
loop and modify the $blog_id
variable if it's for a single site.
Sidenote, I also would suggest adding this as a WP CLI command to perform this work rather than embedding it into a file on the server. Slightly more flexible, and execution can also be stopped immediately if things go sideways.
function delete_duplicates() {
global $wpdb;
$blog_ids = $wpdb->get_results(
"SELECT blog_id FROM {$wpdb->base_prefix}blogs", ARRAY_A
);
foreach ( $blog_ids as $blog ) :
$blog_id = $blog['blog_id'];
$sql = $wpdb->prepare(
"SELECT comment_author,comment_content,comment_ID FROM {$wpdb->base_prefix}%d_comments", $blog_id
);
$all_comments = $wpdb->get_results( $sql );
$duplicate_comments = [];
if ( ! empty( $all_comments ) ) :
foreach ( $all_comments as $key => $comment ) :
$comment_id = $comment->comment_ID;
$comment_author = $comment->comment_author;
//escape comment content when fetching so it compares appropriately in the $sql prepared statement
$escaped_content = $wpdb->_real_escape ( $comment->comment_content );
// find all comments with content matching current comment content and author, except current comment ID
$sql = $wpdb->prepare(
"SELECT comment_ID FROM {$wpdb->base_prefix}%d_comments WHERE comment_content = '" . $escaped_content . "' AND comment_ID != %d AND comment_author = %s", $blog_id, $comment_id, $comment_author
);
$duplicate_comments[] = $wpdb->get_var( $sql );
endforeach;
// only add duplicate comment IDs once into array
$duplicate_comments = array_unique( $duplicate_comments );
// actually deleting comments that are duplicated
if ( ! empty( $duplicate_comments ) ) :
foreach ( $duplicate_comments as $duplicate_key => $duplicate_comment ) :
if ( ! empty ( $duplicate_comment ) ) :
$table = $wpdb->prefix . $blog_id . '_comments';
$delete = $wpdb->delete( $table, [ 'comment_ID' => $duplicate_comment ], [ '%d' ] );
endif;
endforeach;
endif;
endif;
endforeach;
}
Upvotes: 0
Reputation: 115
You could do a select all query and then loop through those. While in the loop do a query that delete anything that is the same and doesn't have the ID of current index. Backup first.
Update:
I prefer to keep this kind of code in a separate file in the root directory.
SO make a new file in root and call it whatever you want and then add this code. Run the file AFTER YOU BACKUP your comment and comment meta tables.
You could do a select all query and then loop through those. While in the loop do a query that delete anything that is the same and doesn't have the ID of current index. Backup first.
Update:
I prefer to keep this kind of code in a separate file in the root directory.
SO make a new file in root and call it whatever you want and then add this code. Run the file AFTER YOU BACKUP your comment and comment meta tables.
<?php
require('./wp-load.php');
global $wpdb; // loads the DB object
$comments = $wpdb->get_results("SELECT * FROM ".$wpdb->prefix."comments");
foreach((array)$comments as $key => $comment)
{
$id_to_check = $comment->comment_ID; // keep this comment ID
$get_dupes = $wpdb->get_results("SELECT * FROM ".$wpdb->prefix."comments WHERE comment_content = '".$comment->comment_content."' AND comment_ID != $id_to_check OR comment_date = '".$comment->comment_date."' AND comment_ID != '".$id_to_check."' ");
foreach((array)$get_dupes as $dkey => $dupe)
{
$wpdb->query("DELETE FROM ".$wpdb->prefix."commentmeta WHERE comment_id = '".$dupe->comment_ID."'"); // delete duplicate comment meta
}
$wpdb->query("DELETE FROM ".$wpdb->prefix."comments WHERE comment_ID = '".$dupe->comment_ID."'"); // delete duplicate comment
}
echo 'all done!'
?>
Upvotes: 1
Reputation: 127
first count number of comments ...
example : SELECT COUNT(*) FROM wp_comments WHERE comment_date='blahblah'
then store the result in a variable ... for example $comment_count then ...
DELETE FROM wp_comments WHERE comment_date='blahblah' LIMIT N
replace N with $comment_count-1
Upvotes: 0