SQL Gabung tabel yang sama berdasarkan cap waktu dan tingkat inventaris

Menerjemahkan ke dalam SQL tidak terlalu sulit, tetapi kinerjanya mungkin buruk. Ini akan memberi Anda stempel waktu saat produk tersedia kembali:

SELECT inv.*,
 ( SELECT MIN(`inv2`.`in_stock_at`)
   FROM inventories AS inv2
   WHERE inv2.`product_id` = inv.`product_id`   -- same product
     AND inv2.`pusher_id` = `inv`.`pusher_id`   -- same pusher
     AND `inv2`.`created_at` > inv.`created_at` -- later timestamp
     AND `inv2`.`item_count` > 0                -- in stock
 ) AS inStockAgain_at
from `inventories` AS inv
WHERE inv.`item_count` <= 0   -- out of stock
 -- AND inv.`product_id`=9

Sunting:

Menghapus baris berurutan dengan stok nol lebih rumit:

SELECT inv.*, dt.inStockAgain_at
FROM inventories AS inv
JOIN
 ( 
   SELECT product_id, pusher_id, 
      MIN(created_at) AS min_created_at,
     inStockAgain_at
   FROM
    (
      SELECT product_id, pusher_id, created_at,
       ( SELECT MIN(inv2.created_at)
         FROM inventories AS inv2
         WHERE inv2.product_id = inv.product_id -- same product
           AND inv2.pusher_id = inv.pusher_id   -- same pusher
           AND inv2.created_at > inv.created_at -- later timestamp
           AND inv2.item_count > 0              -- in stock
       ) AS inStockAgain_at
      FROM inventories AS inv
      WHERE inv.item_count <= 0  
    ) AS dt
   GROUP BY product_id, pusher_id, inStockAgain_at
 ) AS dt
ON inv.product_id = dt.product_id
AND inv.pusher_id = dt.pusher_id 
AND inv.created_at = dt.min_created_at 

Lihat biola