SQL: lookup values from a table with multiple conditions to return final calculation

Question

I am trying to build a query that calculates final revenue based off a number of conditions that affect the cost of items bought from multiple stores over a period of time. Each store/item/location has difference costs.

Currently I have scheduled, partitioned tables showing sales per store that update how many apples/pears I buy each day. This feeds into a table that looks like Table B below. Currently the costs are manually updated in the query as cost per item, per store. However it hasn't been accounting for differences in cities or delivery fees, so total costs will be inaccurate.

As there are so many cost variations it seemed easier to update a central table with different costs breakdowns. For example Table A contains the list of items and cost per items at different stores, cities and if delivery has cost us money.

Rather than manually update one long query with lots of conditional statements per store, Can I have one query that matches the costs just from Table A whenever it is updated?

Thanks

Table A:

Item	Store	City	Costper item	Delivery	Delivery fee per item
Apples	SnakMarket	Townville	$1	y	$0.5
Pears	SnakMarket	Townville	$3	y	$0.5
Apples	SnakMarket	Cityshire	$1.50	n	$0.0
Pears	SnakMarket	Cityshire	$3.50	n	$0.0
Apples	DollarFood	Townville	$2	y	$0.75
Pears	DollarFood	Townville	$4	y	$0.75
Apples	DollarFood	Cityshire	$3	n	$0.0
Pears	DollarFood	Cityshire	$4	n	$0.0

Table B should have the outputs that groups the costs similarly to below.

Table B:

Item	Quantity	Total Revenue
Apples	350	$xxxx
Pears	601	$xxxx

Answer 1

You haven't displayed your quantities table which would be helpful, but from my understanding, it looks something like this:

Date	Item	Store	City	Quantity
2022/09/29	Pear	SnakMarket	Townville	69420
2022/09/29	Apple	SnakMarket	Townville	42069
2022/09/29	Pear	SnakMarket	Cityshire	10000
2022/09/29	Apple	SnakMarket	Cityshire	45454

... etc

If your table looks something like the above (irrespective of column order), you can perform a LEFT JOIN to add the costings per item

SELECT
A.Date,
A.Item,
A.Store,
A.City,
A.Quantity,
B.Costperitem,
B.Delivery,
B.Deliveryfee
FROM
`Quantity Table` AS A
LEFT JOIN
`Table 1` AS B
ON
A.Item = B.Item
AND
A.Store = B.Store
AND
A.City = B.City

This will combine your data and you will end up with and output like:

Date	Item	Store	City	Quantity	Costperitem	Delivery	Deliveryfee
2022/09/29	Pear	SnakMarket	Townville	69420	3	y	0.5
2022/09/29	Apple	SnakMarket	Townville	42069	1	y	0.5
2022/09/29	Pear	SnakMarket	Cityshire	10000	3.5	n	0
2022/09/29	Apple	SnakMarket	Cityshire	45454	1.5	n	0

... etc

From this, you should be able to work out your groupings to get the total revenue generated.