mysql sum with group by query need specific sum - mysql

Question

Run code in http://rextester.com/OZKM95674
I am trying to come up with an fast and easy way to get the sum of quantity for all variations of an item but also include data such as all tags (comma seperated) and one of the images for an item (doesn't matter which one). There are many tables involve shown below:
Query 1: This query below gets the data I want for quantity but is missing data I need for my application (see query 2).
SELECT phppos_items.item_id,
phppos_items.name,
SUM(phppos_location_item_variations.quantity) as quantity
FROM `phppos_items`
LEFT JOIN `phppos_item_variations`
ON `phppos_item_variations`.`item_id` = `phppos_items`.`item_id`
LEFT JOIN `phppos_location_item_variations`
ON `phppos_location_item_variations`.`item_variation_id` = `phppos_item_variations`.`id`
and `phppos_location_item_variations`.`location_id` = 1
GROUP BY `phppos_items`.`item_id`
Result:
+---------+------+----------+
| item_id | name | quantity |
+---------+------+----------+
| 1 | TEST | 10 |
+---------+------+----------+
Query 2: But in the application I actually need more data about an item such as tags and one image (could be many just need one). I need the exact output as below but instead of the quantity being 60 I need it to be 20 like before. I know the reason this is happening because when I do group by; there is more than one row because there are 3 tags and 1 image.
SELECT phppos_items.item_id,
phppos_items.name, SUM(phppos_location_item_variations.quantity) as quantity,
`phppos_item_images`.`image_id` as `image_id`,
GROUP_CONCAT(DISTINCT phppos_tags.name) as tags
FROM `phppos_items`
LEFT JOIN `phppos_item_variations`
ON `phppos_item_variations`.`item_id` = `phppos_items`.`item_id`
LEFT JOIN `phppos_location_item_variations`
ON `phppos_location_item_variations`.`item_variation_id` = `phppos_item_variations`.`id`
and `phppos_location_item_variations`.`location_id` = 1
LEFT JOIN `phppos_items_tags`
ON `phppos_items_tags`.`item_id` = `phppos_items`.`item_id`
LEFT JOIN `phppos_tags`
ON `phppos_tags`.`id` = `phppos_items_tags`.`tag_id`
LEFT JOIN `phppos_item_images`
ON `phppos_items`.`item_id` = `phppos_item_images`.`item_id`
WHERE `phppos_items`.`deleted` = 0
AND `phppos_items`.`system_item` = 0
GROUP BY `phppos_items`.`item_id`
+---------+------+----------+----------+--------------------+
| item_id | name | quantity | image_id | tags |
+---------+------+----------+----------+--------------------+
| 1 | TEST | 60 | 1 | test,test 2,test 3 |
+---------+------+----------+----------+--------------------+
What is an efficient way to get all this data in one query?
Sample data:
phppos_items:
+---------+------+
| item_id | name |
+---------+------+
| 1 | TEST |
+---------+------+
phppos_item_variations:
+---------+----+
| item_id | id |
+---------+----+
| 1 | 1 |
+---------+----+
phppos_location_item_variations:
+-------------------+----------+
| item_variation_id | quantity |
+-------------------+----------+
| 1 | 10 |
+-------------------+----------+
phppos_tags:
+--------+----+
| name | id |
+--------+----+
| test | 1 |
| test 2 | 2 |
| test 3 | 3 |
+--------+----+
phppos_items_tags:
+---------+--------+
| item_id | tag_id |
+---------+--------+
| 1 | 1 |
| 1 | 2 |
| 1 | 3 |
+---------+--------+
phppos_item_images:
+---------+----------+
| item_id | image_id |
+---------+----------+
| 1 | 1 |
| 1 | 4 |
+---------+----------+
Tables involved
CREATE TABLE `phppos_items` (
`name` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
`item_id` int(10) NOT NULL AUTO_INCREMENT,
`deleted` int(1) NOT NULL DEFAULT '0',
`system_item` int(1) NOT NULL DEFAULT '0',
PRIMARY KEY (`item_id`),
UNIQUE KEY `item_number` (`item_number`),
KEY `deleted` (`deleted`),
KEY `deleted_system_item` (`deleted`,`system_item`),
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
CREATE TABLE `phppos_item_variations` (
`id` int(10) NOT NULL AUTO_INCREMENT,
`item_id` int(10) NOT NULL,
PRIMARY KEY (`id`),
KEY `phppos_item_variations_ibfk_1` (`item_id`),
CONSTRAINT `phppos_item_variations_ibfk_1` FOREIGN KEY (`item_id`) REFERENCES `phppos_items` (`item_id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
CREATE TABLE `phppos_location_item_variations` (
`item_variation_id` int(10) NOT NULL,
`location_id` int(10) NOT NULL,
`quantity` int(1) DEFAULT NULL,
`reorder_level` decimal(23,10) DEFAULT NULL,
`replenish_level` decimal(23,10) DEFAULT NULL,
PRIMARY KEY (`item_variation_id`,`location_id`),
KEY `phppos_item_attribute_location_values_ibfk_2` (`location_id`),
CONSTRAINT `phppos_item_attribute_location_values_ibfk_1` FOREIGN KEY (`item_variation_id`) REFERENCES `phppos_item_variations` (`id`),
CONSTRAINT `phppos_item_attribute_location_values_ibfk_2` FOREIGN KEY (`location_id`) REFERENCES `phppos_locations` (`location_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
CREATE TABLE `phppos_items_tags` (
`item_id` int(11) NOT NULL,
`tag_id` int(11) NOT NULL,
PRIMARY KEY (`item_id`,`tag_id`),
KEY `phppos_items_tags_ibfk_2` (`tag_id`),
CONSTRAINT `phppos_items_tags_ibfk_1` FOREIGN KEY (`item_id`) REFERENCES `phppos_items` (`item_id`),
CONSTRAINT `phppos_items_tags_ibfk_2` FOREIGN KEY (`tag_id`) REFERENCES `phppos_tags` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
CREATE TABLE `phppos_tags` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`ecommerce_tag_id` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`last_modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`deleted` int(1) NOT NULL DEFAULT '0',
`name` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `tag_name` (`name`),
KEY `deleted` (`deleted`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |
CREATE TABLE `phppos_item_images` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`title` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`alt_text` varchar(255) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
`item_id` int(11) DEFAULT NULL,
`item_variation_id` int(10) DEFAULT NULL,
`ecommerce_image_id` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
`image_id` int(11) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `phppos_item_images_ibfk_1` (`item_id`),
KEY `phppos_item_images_ibfk_2` (`image_id`),
KEY `phppos_item_images_ibfk_3` (`item_variation_id`),
CONSTRAINT `phppos_item_images_ibfk_1` FOREIGN KEY (`item_id`) REFERENCES `phppos_items` (`item_id`),
CONSTRAINT `phppos_item_images_ibfk_2` FOREIGN KEY (`image_id`) REFERENCES `phppos_app_files` (`file_id`),
CONSTRAINT `phppos_item_images_ibfk_3` FOREIGN KEY (`item_variation_id`) REFERENCES `phppos_item_variations` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci |

Answer 1

You said your first query already works so now you need get the remaining information
SQL DEMO
SELECT Q1.*, Q2.tags, Q3.image_id
FROM ( SELECT phppos_items.item_id,
phppos_items.name,
SUM(phppos_location_item_variations.quantity) as quantity
FROM `phppos_items`
LEFT JOIN `phppos_item_variations`
ON `phppos_item_variations`.`item_id` = `phppos_items`.`item_id`
LEFT JOIN `phppos_location_item_variations`
ON `phppos_location_item_variations`.`item_variation_id` = `phppos_item_variations`.`id`
and `phppos_location_item_variations`.`location_id` = 1
GROUP BY `phppos_items`.`item_id` ) as Q1
LEFT JOIN ( SELECT i.item_id,
GROUP_CONCAT(DISTINCT t.name) as tags
FROM phppos_items i
LEFT JOIN phppos_items_tags it
ON i.item_id = it.item_id
LEFT JOIN phppos_tags t
ON it.tag_id = t.id
GROUP BY i.item_id
) as Q2
ON Q1.item_id = Q2.item_id
LEFT JOIN ( SELECT item_id, MIN(image_id) as image_id
FROM phppos_item_images
GROUP BY item_id
) as Q3
ON Q1.item_id = Q3.item_id
OUTPUT