SUMmarize 3 columns from 2 different table in SQL - mysql

Question

I have 3 database table. The one I store sell data like invoice number, due date, issue date. The second table I have the sell record id stored from previous table, there I store the ammount the person have payed (something like the customer payed only a half of the total price). In the third table I store the products and every row has the sell record id for backreference, in this table I have quantity and subtotal (quantity * price).
What I need is select all the record from first table and based on the sell_id I have to summarize how much they payed from the second table, summarize how many products one purchased and how much does it cost.
I need a little guidance to the right solution because I am stuck.
So far I came to this uggly sollution:
SELECT
(SELECT SUM(payment.sellpayment_amount) FROM es_sellpayment payment WHERE sell.sell_id = payment.sell_id) AS payed,
(SELECT SUM(product.sellproduct_quantity) FROM es_sellproduct product WHERE sell.sell_id = product.sell_id) AS quantity,
(SELECT SUM(product.sellproduct_total) FROM es_sellproduct product WHERE sell.sell_id = product.sell_id) AS total
FROM es_sell sell
It works I get the correct result, but I am unsure/unaware how this will impact later on the performance of the website. I tried the classic left join which gave me wrong results. I am also thinking storing permanently these 3 values on the main table; but this would be the lest preferable method because I had to make at lest 2 seperate SQL queries to retrieve the records.
CREATE TABLE `es_sell` (
`sell_id` int(11) NOT NULL,
`sell_invoice` int(11) NOT NULL,
`sell_note` text COLLATE utf8mb4_unicode_ci NOT NULL,
`sell_deliver` datetime NOT NULL,
`sell_issued` datetime NOT NULL,
`sell_due` datetime NOT NULL,
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `es_sellproduct` (
`sellproduct_id` int(11) NOT NULL,
`product_id` int(11) NOT NULL,
`sellproduct_quantity` int(11) NOT NULL,
`sellproduct_price` int(11) NOT NULL,
`pricetype_id` int(11) NOT NULL,
`sellproduct_total` decimal(11,3) NOT NULL,
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `es_sellpayment` (
`sellpayment_id` int(11) NOT NULL,
`sellpayment_amount` decimal(11,3) NOT NULL,
`sell_id` int(11) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

Answer 1

Use sub-queries to aggregate the associated tables to ensure that you're only ever joining one row to one row...
SELECT
sell.sell_id,
payment.payed,
product.quantity,
product.total
FROM
es_sell sell
LEFT JOIN
(
SELECT
sell_id,
SUM(sellpayment_amount) AS payed
FROM
es_sellpayment payment
GROUP BY
sell_id
)
payment
ON payment.sell_id = sell.sell_id
LEFT JOIN
(
SELECT
sell_id,
SUM(sellproduct_quantity) AS quantity,
SUM(sellproduct_total ) AS total
FROM
es_sellproduct
GROUP BY
sell_id
)
product
ON product.sell_id = sell.sell_id
If sell_id isn't unique in the sell table, you can aggregate again in the outer query.