Get the right data for a specific id - sql

Question

I want to get the prices for each product for a specific place. Here's what I have done so far.
SELECT pl.id AS place_id,
pl.data_name AS place_name,
pp.data_price AS product_price,
pp.date_updated AS price_updated
FROM places AS pl
JOIN products AS pr
ON pl.id = pr.id_place
JOIN products_prices AS pp
WHERE pp.id_product = '30'
GROUP BY pl.id, pp.data_price, pp.date_updated
ORDER BY pp.data_price DESC, pp.date_updated DESC
As you can see from the image above, product_price and price_updated are all the same. place_name also shows 3 places that does not have the product with id 30.
Here's how it should looks like (cheapest, most recent product purchase on top):
place_id place_name product_price price_updated
3 ICA Maxi 4.95 2018-05-16
1 ICA Supermarket 5.90 2018-05-27
26 ICA Skutan 6.50 2018-05-29
Here's the database structure:
CREATE TABLE IF NOT EXISTS `places` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`data_name` tinytext NOT NULL,
`data_address` text,
`data_address_city` tinytext NOT NULL,
`data_coordinates` varchar(50) NOT NULL,
UNIQUE KEY `id` (`id`)
);
INSERT INTO `places` (`id`, `data_name`, `data_address`, `data_address_city`, `data_coordinates`) VALUES
(1, 'ICA Supermarket', 'Björkhagsgatan 9', 'Skoghall', '59.324971,13.467291'),
(2, 'ICA Maxi', 'Bergviks Köpcentrum', 'Karlstad', '59.376563,13.428787'),
(3, 'ICA Kvantum', 'Bivägen 11', 'Hammarö', '59.343388,13.504583'),
(4, 'IKEA', 'Bergviksvägen 43', 'Karlstad', '59.379032,13.420646'),
(5, 'Karlstad Naprapatklinik', 'Västra Torggatan 15', 'Karlstad', '59.381379,13.501683'),
(9, 'Besök i Borgvik AB', '', 'Borgvik', '59.348261,12.954707'),
(23, 'Mariebergsskogen', '', 'Karlstad', '59.369403,13.486485'),
(24, 'Happy Price', 'Brehogsvägen 20', 'Tanumshede', '58.723730,11.344768'),
(25, 'Trekanten Kök & Bar', 'Parkvägen 2', 'Hamburgsund', '58.552733,11.270998'),
(26, 'ICA Skutan', 'Strandvägen', 'Hamburgsund', '58.552122,11.270898');
CREATE TABLE IF NOT EXISTS `products` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`id_place` int(11) NOT NULL,
`data_barcode` text NOT NULL,
`data_name` text NOT NULL,
`data_weight` text NOT NULL,
`data_weight_type` text NOT NULL,
UNIQUE KEY `id` (`id`)
);
INSERT INTO `products` (`id`, `id_place`, `data_barcode`, `data_name`, `data_weight`, `data_weight_type`) VALUES
(7, 3, '7311070008494', 'Pågen Lantbröd', '650', 'g'),
(8, 3, '7310618084808', 'Grumme citronsåpa', '750', 'ml'),
(9, 3, '7318690079835', 'ICA Basic toalettpapper', '', ''),
(12, 1, '7318690134640', 'ICA Basic Milk & Caramel', '100', 'g'),
(18, 3, '7310380512103', 'ICA Home dishmatic refillsvamp', '', ''),
(19, 3, '7340109200684', 'Plastkasse', '', ''),
(20, 1, '7310751163903', 'ICA tonfisk filébitar i vatten', '185', 'g'),
(24, 1, '7310865001818', 'Arla mellanmjölk', '1.5', 'kg'),
(25, 1, '7318690079712', 'ICA kattsand (klumpbildande, ej parfym)', '6', 'kg'),
(29, 26, '3068320055008', 'Evian mineralvatten', '500', 'mL'),
(30, 26, '7318690134640', 'ICA Basic Milk & Caramel', '100', 'g'),
(33, 2, '0', 'ICA Basic Milk & Caramel', '100', 'g');
CREATE TABLE IF NOT EXISTS `products_prices` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`id_product` int(11) NOT NULL,
`id_transaction` int(11) NOT NULL,
`data_price` decimal(10,2) NOT NULL,
`data_amount` tinytext NOT NULL,
`data_discount` tinytext,
`data_discount_amount` tinytext,
`data_discount_sum` tinytext,
`data_pant` tinytext,
`date_updated` date NOT NULL,
UNIQUE KEY `id` (`id`)
);
INSERT INTO `products_prices` (`id`, `id_product`, `id_transaction`, `data_price`, `data_amount`, `data_discount`, `data_discount_amount`, `data_discount_sum`, `data_pant`, `date_updated`) VALUES
(1, 1, 907, 18.90, '4', '', '2', '30', NULL, '2018-05-18'),
(2, 12, 907, 4.90, '4', '', '', '', NULL, '2018-05-18'),
(5, 4, 904, 18.90, '1', '', '', '', NULL, '2018-05-18'),
(6, 14, 904, 14.90, '1', '', '', '', NULL, '2018-05-18'),
(17, 19, 936, 2.00, '1', '', '', '', NULL, '2018-05-21'),
(18, 21, 947, 23.90, '1', '', '', '', NULL, '2018-05-23'),
(19, 22, 947, 10.50, '1', '', '', '', NULL, '2018-05-23'),
(20, 20, 947, 15.90, '1', '', '', '', NULL, '2018-05-23'),
(21, 13, 947, 49.90, '1', '', '', '', NULL, '2018-05-23'),
(22, 23, 948, 14.90, '1', '', '', '', NULL, '2018-05-24'),
(23, 24, 961, 14.90, '1', NULL, NULL, NULL, NULL, '2018-05-27'),
(24, 12, 961, 5.90, '4', NULL, NULL, NULL, NULL, '2018-05-27'),
(32, 28, 967, 8.50, '2', NULL, NULL, NULL, NULL, '2018-05-28'),
(33, 29, 972, 12.90, '1', NULL, NULL, NULL, '1', '2018-05-29'),
(34, 30, 973, 6.50, '2', NULL, NULL, NULL, NULL, '2018-05-29'),
(35, 31, 976, 10.00, '1', NULL, NULL, NULL, NULL, '2018-05-30'),
(36, 32, 976, 10.00, '1', NULL, NULL, NULL, NULL, '2018-05-30');

Answer 1

As mentioned in my comment to your request: You forgot the ON clause that links the products_prices table to the other two.
MariaDB nastily converts your inner join into a cross join instead of raising an error as it should. What this gives you is: select all prices for product 30 combined with all places multiplied with the number of products therein, instead of just combined with the product's place.
By the way: I'd put table products first in the FROM clause, because this is the base (you want product 30). Then join the product's prices and the product's place.
There is no reason to group your data, as you only want to list the prices. You are not aggregating anything. So you get:
SELECT
pl.id AS place_id,
pl.data_name AS place_name,
pp.data_price AS product_price,
pp.date_updated AS price_updated
FROM products AS pr
JOIN products_prices AS pp ON pp.id_product = pr.id
JOIN places pl ON pl.id = pr.id_place
WHERE pr.id = 30
ORDER BY pp.data_price DESC, pp.date_updated DESC;

Answer 2

Try this:
SELECT PL.id AS place_id,
PL.data_name AS place_name,
PP.data_price AS product_price,
PP.date_updated AS price_updated
FROM products_prices PP
JOIN products PR
ON PR.id = PP.id_product
JOIN places PL
ON PL.id = PR.id_place
WHERE PR.id = '30'