SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 4 
WHERE 
  cscart_products_categories.product_id IN (
    68974, 68973, 68972, 68971, 68970, 68969, 
    68968, 68967, 68966, 68965, 68964, 
    68963, 68962, 68961, 68960, 68959, 
    68958, 68957, 68956, 68955, 68954, 
    68953, 68952, 68951, 68950, 68949, 
    68948, 68947, 68946, 68945, 68321, 
    68290, 68289, 68288, 68286, 68285, 
    68284, 68283, 68282, 68281
  ) 
GROUP BY 
  cscart_products_categories.product_id