WordPress database error: [Not unique table/alias: 'wp_postmeta']

SELECT * FROM wp_posts INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id ) INNER JOIN wp_postmeta ON wp_posts.ID = wp_postmeta.post_id LEFT JOIN wp_sticky ON wp_sticky.sticky_post_id = wp_posts.ID WHERE 1=1 AND wp_posts.post_type = 'display_type' AND ((wp_posts.post_status <> 'trash' AND wp_posts.post_status <> 'auto-draft')) AND (
( wp_postmeta.meta_key = 'name' AND CAST(wp_postmeta.meta_value AS CHAR) = 'photocrati-nextgen_basic_thumbnails' )
) AND ( wp_postmeta.meta_key = 'enclosure' ) ORDER BY (wp_sticky.sticky_status = 2 AND wp_sticky.sticky_status IS NOT NULL) DESC, DATE_FORMAT(wp_posts.post_date,'%Y-%m-%d') DESC, (wp_sticky.sticky_status = 1 AND wp_sticky.sticky_status IS NULL) DESC, DATE_FORMAT(wp_posts.post_date,'%T') DESC

WordPress database error: [Not unique table/alias: 'wp_postmeta']

SELECT * FROM wp_posts INNER JOIN wp_postmeta ON ( wp_posts.ID = wp_postmeta.post_id ) INNER JOIN wp_postmeta ON wp_posts.ID = wp_postmeta.post_id LEFT JOIN wp_sticky ON wp_sticky.sticky_post_id = wp_posts.ID WHERE 1=1 AND wp_posts.post_type = 'display_type' AND ((wp_posts.post_status <> 'trash' AND wp_posts.post_status <> 'auto-draft')) AND (
( wp_postmeta.meta_key = 'name' AND CAST(wp_postmeta.meta_value AS CHAR) = 'photocrati-nextgen_basic_thumbnails' )
) AND ( wp_postmeta.meta_key = 'enclosure' ) ORDER BY (wp_sticky.sticky_status = 2 AND wp_sticky.sticky_status IS NOT NULL) DESC, DATE_FORMAT(wp_posts.post_date,'%Y-%m-%d') DESC, (wp_sticky.sticky_status = 1 AND wp_sticky.sticky_status IS NULL) DESC, DATE_FORMAT(wp_posts.post_date,'%T') DESC