MySQL INNER JOIN of 3 tables with count and totals - mysql

Question

I have the following sample database set up -
CREATE TABLE IF NOT EXISTS `companies`(
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`company` varchar(75) NOT NULL,
PRIMARY KEY (`id`)
)ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;
INSERT INTO `companies` (`id`, `company`) VALUES
(1, 'Acme Widget Company'),
(2, 'Intrepid Inc.'),
(3, 'Allied Corp.');
CREATE TABLE IF NOT EXISTS `companies_customers` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`company_id` int(11) NOT NULL,
`customer_id` int(11) NOT NULL,
PRIMARY KEY (`id`)
)ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ;
INSERT INTO `companies_customers` (`id`, `company_id`, `customer_id`) VALUES
(1, 2, 1),
(2, 2, 2),
(3, 2, 4),
(4, 1, 3),
(5, 1, 1);
CREATE TABLE IF NOT EXISTS `customers` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`firstname` varchar(25) NOT NULL,
`lastname` varchar(50) NOT NULL,
PRIMARY KEY (`id`)
)ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=5 ;
INSERT INTO `customers` (`id`, `firstname`, `lastname`) VALUES
(1, 'John', 'Smith'),
(2, 'Sue', 'Jones'),
(3, 'David', 'Flanders'),
(4, 'Kathy', 'Freeman');
CREATE TABLE IF NOT EXISTS `orders` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`customer_id` int(11) NOT NULL,
`amount` decimal(10,0) NOT NULL,
PRIMARY KEY (`id`)
)ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ;
INSERT INTO `orders` (`id`, `customer_id`, `amount`) VALUES
(1, 1, 500),
(2, 3, 1000),
(3, 1, 250),
(4, 4, 800),
(5, 4, 100);
I need to write a query which retrieves a list of all company names, a count of the number of customers in each company, and a sum of the customers orders in each company, like this -
Company Total Customers All Orders Total
Acme Widget Company 2 750
Intrepid Inc. 3 1650
Allied Corp. 0 0
I nearly have it resolved with the following SQL -
SELECT company AS 'Company', customersCount AS 'Total Customers', customerOrdersTotal AS 'All Orders Total'
FROM
( SELECT cc.customer_id, SUM(innerQuery.ordersTotal) customerOrdersTotal
FROM (SELECT cu.id customerId, SUM(amount) ordersTotal
FROM customers cu
JOIN orders o ON o.customer_id = cu.id
GROUP BY customerId
) innerQuery
JOIN companies_customers cc ON innerQuery.customerId = cc.customer_id
GROUP BY cc.customer_id
) inner_1
RIGHT JOIN
( SELECT cc.id, c.company, COUNT(*) customersCount
FROM companies c
JOIN companies_customers cc ON c.id = cc.company_id
GROUP BY c.id
) inner_2
ON inner_1.customer_id = inner_2.id
It does not print out the company (Allied) without a customer or total. So close, I just need a nudge in the right direction. Thanks.

Answer 1

Since the orders are linked to the companies via the customers, I don't think you need to perform two separate subqueries and join them; rather, I think you can just write:
SELECT companies.company AS "Company",
IFNULL(COUNT(DISTINCT companies_customers.customer_id), 0) AS "Total Customers",
IFNULL(SUM(orders.amount), 0) AS "All Orders Total"
FROM companies
LEFT
JOIN companies_customers
ON companies_customers.company_id = companies.id
LEFT
JOIN orders
ON orders.customer_id = companies_customers.customer_id
GROUP
BY companies.id
;
Edited to add: That said, I have to say that the schema doesn't really make sense to me. You have a many-to-many relationship between customers and companies — so, for example, John Smith is a customer of Acme Widget Company and of Intrepid Inc. — but then orders are just a property of the customer, not of the company. This means that if an order belongs to John Smith, then it necessarily belongs both to Acme Widget Company and to Intrepid Inc.. I don't think that can be right. Instead of having a customer_id field, I think orders needs to have a companies_customers_id field.

Answer 2

I have 3 table that to keep team,tournament_round AND score_team_member about competition TEAM_A Vs TEAM_B ,multiple of round.(1,2,3...n) and multiple of members of team there is score by oneself.This code above are useful very much.
SELECT team.name AS "TEAM",team.id,
IFNULL(COUNT(DISTINCT `tournament_round`.id), 0) AS "TotalWin",
IFNULL(SUM(`score_team_member`.`score`)/(select count(*) from `team_member`where team_id=team.id group by team_id ), 0) AS "ScoreofTeam"
FROM `team`
LEFT
JOIN `tournament_round`
ON `tournament_round`.team_winner_id = `team`.id
LEFT
JOIN `score_team_member`
ON `score_team_member`.team_id = `team`.id
WHERE `team`.thematch_id='6' AND `team`.`category1`='MEP'
GROUP BY `team`.id ORDER by `TotalWin`DESC ,`ScoreofTeam` DESC
Sample out put click here JPG
Table Designer JPG