WITH RECURSIVE tree ( data , id , level , path ) AS
  (

    /* FATHER */
    SELECT
      FATHER.category_title, FATHER.category_id , 0 , CAST(\'\' AS CHAR(1000))
    FROM category AS FATHER
    WHERE FATHER.category_parent_id IS NULL

    UNION ALL

    /* CHILD */
    SELECT
      CHILD.category_title , CHILD.category_id , TREE.level + 1 , CONCAT( TREE.path , \'/\' , CHILD.category_link )
    FROM category AS CHILD
    INNER JOIN tree AS TREE
      ON TREE.id = CHILD.category_parent_id

  )

/* RESULT TREE */
SELECT CONCAT( SPACE(level) , data ) AS data , id , level ,  path
FROM tree
ORDER BY path