Query to return total of product item required on each delivery date - woocommerce and wordpress

scubadude :

I am working on sql queries in woocommerce and wordpress where I have three tables that need to join as a query result. Basically, I'd like to list delivery date with total item that needs on that day across multiple order id. Here is what the table looks like:

TABLE_A
| id    | order_id |  date                |
| 1     | 20       |  2020-04-12 00:00:00 |
| 2     | 21       |  2020-04-14 00:00:00 |
| 3     | 22       |  2020-04-14 00:00:00 |

 TABLE_B
| order_item_id | order_item_name | order_id |
| 50            | Item A          | 20       |
| 51            | Item B          | 20       |
| 52            | Item C          | 21       |
| 53            | Item A          | 21       |
| 54            | Item A          | 22       |

 TABLE_C
| detail_id    | order_item_id   | key        | Value |
| 1            | 50              | qty        | 2     |
| 2            | 51              | qty        | 3     |
| 3            | 52              | qty        | 3     |
| 4            | 53              | qty        | 4     |
| 5            | 54              | qty        | 2     |

Desired Outcome

| date                 | order_item_name | total  |
| 2020-04-12 00:00:00  | Item A          | 2      |
| 2020-04-12 00:00:00  | Item B          | 3      |
| 2020-04-14 00:00:00  | Item C          | 3      |
| 2020-04-14 00:00:00  | Item A          | 6      |

What i did:

SELECT 
   date,
   order_item_name,
   sum(value) as Total
FROM
   TABLE_A
INNER JOIN TABLE_B USING (order_id)
INNER JOIN TABLE_C USING (order_item_id)
GROUP BY order_item_id

But i cant seem to get the total correct, any help will be much appreciated, thank you

Mansi :

SELECT 
   date,
   order_item_name,
   sum(value) as Total
FROM
   TABLE_A
INNER JOIN TABLE_B USING (order_id)
INNER JOIN TABLE_C USING (order_item_id)
GROUP BY order_item_name,date
ORDER BY order_id ASC

Since you need the items date wise, group by needs to be performed on item name and date. This query will fetch the desired result.