WordPress Database/table error

Hi,
I’m getting the below error in my logs multiple times (sometimes up to 10) per day. I’m fairly new to WordPress and don’t have a clue where to start looking. It seems to have been going on for quite some time.

Anyone have an idea on where to start? Thanks for any assistance that can be provided.

Thanks,
Mkc

Error –
[28-Apr-2015 03:35:38 UTC] WordPress database error Not unique table/alias: ‘wp_comments’ for query SELECT SQL_CALC_FOUND_ROWS wp_posts.*, AVG( wp_commentmeta.meta_value ) as average_rating , AVG( wp_commentmeta.meta_value ) as average_rating FROM wp_posts INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id ) INNER JOIN wp_postmeta AS mt1 ON ( wp_posts.ID = mt1.post_id ) INNER JOIN wp_postmeta AS mt2 ON ( wp_posts.ID = mt2.post_id ) INNER JOIN wp_postmeta AS mt3 ON ( wp_posts.ID = mt3.post_id )
LEFT OUTER JOIN wp_comments ON(wp_posts.ID = wp_comments.comment_post_ID)
LEFT JOIN wp_commentmeta ON(wp_comments.comment_ID = wp_commentmeta.comment_id)

LEFT OUTER JOIN wp_comments ON(wp_posts.ID = wp_comments.comment_post_ID)
LEFT JOIN wp_commentmeta ON(wp_comments.comment_ID = wp_commentmeta.comment_id)
WHERE 1=1 AND (
( wp_postmeta.meta_key = ‘_visibility’ AND CAST(wp_postmeta.meta_value AS CHAR) IN (‘visible’,’catalog’) )
AND
( mt1.meta_key = ‘_stock_status’ AND CAST(mt1.meta_value AS CHAR) = ‘instock’ )
AND
( mt2.meta_key = ‘_visibility’ AND CAST(mt2.meta_value AS CHAR) IN (‘visible’,’catalog’) )
AND
( mt3.meta_key = ‘_stock_status’ AND CAST(mt3.meta_value AS CHAR) = ‘instock’ )
) AND wp_posts.post_type = ‘product’ AND (wp_posts.post_status = ‘publish’) AND ( wp_commentmeta.meta_key = ‘rating’ OR wp_commentmeta.meta_key IS null ) AND ( wp_commentmeta.meta_key = ‘rating’ OR wp_commentmeta.meta_key IS null ) GROUP BY wp_posts.ID ORDER BY average_rating DESC, wp_posts.post_date DESC LIMIT 0, 10 made by require(‘wp-blog-header.php’), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts