Migrates post relationships from Piklist to MetaBox

piklist-relationships-to-metabox.sql

set @row_num:=0;

INSERT INTO wp_mb_relationships
	(
		`to`,
		`type`,
		`order_from`,
		`order_to`,
		`from`
	)

SELECT
	m.post_id AS BelongID,
	CONCAT(pb.post_type, "_to_", p.post_type) AS ID,
	(@row_num:=CASE 
		WHEN @from_id = CAST(m.meta_value AS UNSIGNED)
			THEN @row_num+1
			ELSE 1
		END
	) AS order_from,
	0,
	@from_id := CAST(m.meta_value AS UNSIGNED) AS FromID
	
	FROM wp_postmeta AS m
	JOIN wp_posts AS p ON p.ID = m.post_id
	JOIN ( SELECT ID, post_type FROM wp_posts ) AS pb
		ON pb.ID = m.meta_value
	
	WHERE m.meta_key = '__relate_post'
	
	ORDER BY FromID ASC;