mySQL sum totals from two tables - mysql

I am trying to sum the PRICE from two tables which are connected by another table.
tblcustomer tblappointment tblfinances
---------- -------------- -----------
CustomerID AppointmentID FinancesID
Name CustomerID CustomerID
Price Price
I am trying this code but I am getting an error #1064
SELECT c.CustomerID, (1.p1+2.p2) AS total_price FROM tblcustomer c
LEFT JOIN (SELECT CustomerID, SUM(Price) p1 FROM tblappointment GROUP BY CustomerID) 1 ON 1.CustomerID = c.CustomerID
LEFT JOIN (SELECT CustomerID, SUM(Price) p2 FROM tblfinances GROUP BY CustomerID) 2 ON 2.CustomerID = c.CustomerID;

I do not recommend using aliases that are or start with numbers. More importantly, you need to recognize that the JOINs may not match -- that would be why you are using outer joins in the first place.
So:
SELECT c.CustomerID,
(COALESCE(a.price, 0) + COALESCE(f.price, 0)) AS total_price
FROM tblcustomer c LEFT JOIN
(SELECT CustomerID, SUM(Price) as price
FROM tblappointment
GROUP BY CustomerID
) a
ON a.CustomerID = c.CustomerID LEFT JOIN
(SELECT CustomerID, SUM(Price) as price
FROM tblfinances
GROUP BY CustomerID
) f
ON f.CustomerID = c.CustomerID;

You need to fix aliasing as follows
SELECT c.CustomerID, (t1.p1+t2.p2) AS total_price
FROM tblcustomer c
LEFT JOIN (SELECT CustomerID, SUM(Price) as p1
FROM tblappointment
GROUP BY CustomerID) t1 ON t1.CustomerID = c.CustomerID
LEFT JOIN (SELECT CustomerID, SUM(Price) as p2
FROM tblfinances
GROUP BY CustomerID) t2 ON t2.CustomerID = c.CustomerID;
since aliases can not be totally numeric expressions except they're quoted

Related

How do I find the associated name of a max of a sum in a MySQL query?

I have this schema here, and I need to find the name of the customer with the highest total amount for the orders. I have a SQL query here:
SELECT Name
FROM (SELECT Name, SUM(Amount) AS Total
FROM customer JOIN orders ON cust_id = ID
GROUP BY Name) AS Totals
WHERE Total = (SELECT MAX(Total)
FROM (SELECT Name, SUM(Amount) AS Total
FROM customer JOIN orders ON cust_id = ID
GROUP BY Name) AS X);
But this is very inefficient as it creates the same table twice. Is there any more efficient way to get the name?
If you want customer with the greatest total mount, then you can just join, order by and limit:
select c.name
from customer c
inner join orders o on o.cust_id = c.id
group by c.id, c.name
order by sum(o.amount) desc
limit 1
Note that this does not handle possible top ties. For this, you need a little more code. Instead of ordering, you would typically filter with a having clause:
select c.name
from customer c
inner join orders o on o.cust_id = c.id
group by c.id, c.name
having sum(o.amount) = (
select sum(o1.amount)
from orders o1
group by cust_id
order by sum(o1.amount) desc
limit 1
)
Finally: if you are running MySQL 8.0, this is simpler done with window function rank():
select name
from (
select c.name, rank() over(order by sum(o.amount) desc) rn
from customer c
inner join orders o on o.cust_id = c.id
group by c.id, c.name
) t
where rn = 1

Using SUM with Joins in MySQL returns unexpected result

I have these tables : customers, customer_invoices, customer_invoice_details, each customer has many invoices, and each invoice has many details.
The customer with the ID 574413 has these invoices :
select customer_invoices.customer_id,
customer_invoices.id,
customer_invoices.total_price
from customer_invoices
where customer_invoices.customer_id = 574413;
result :
customer_id invoice_id total_price
574413 662146 700.00
574413 662147 250.00
each invoice here has two details (or invoice lines) :
first invoice 662146:
select customer_invoice_details.id as detail_id,
customer_invoice_details.customer_invoice_id as invoice_id,
customer_invoice_details.total_price as detail_total_price
from customer_invoice_details
where customer_invoice_details.customer_invoice_id = 662146;
result :
detail_id invoice_id detail_total_price
722291 662146 500.00
722292 662146 200.00
second invoice 662147 :
select customer_invoice_details.id as detail_id,
customer_invoice_details.customer_invoice_id as invoice_id,
customer_invoice_details.total_price as detail_total_price
from customer_invoice_details
where customer_invoice_details.customer_invoice_id = 662147;
result :
detail_id invoice_id detail_total_price
722293 662147 100.00
722294 662147 150.00
I have a problem with this query :
select customers.id as customerID,
customers.last_name,
customers.first_name,
SUM(customer_invoices.total_price) as invoice_total,
SUM(customer_invoice_details.total_price) as details_total
from customers
join customer_invoices
on customer_invoices.customer_id = customers.id
join customer_invoice_details
on customer_invoice_details.customer_invoice_id = customer_invoices.id
where customer_id = 574413;
unexpected result :
customerID last_name first_name invoice_total details_total
574413 terry amine 1900.00 950.00
I need to have the SUM of the total_price of the invoices, and the SUM of the total_price of the details for each customer. In this case I'm supposed to get 950 as total_price for both columns (invoice_total& details_total) but it's not the case. what am I doing wrong & how can I get the correct result please. The answers in similar topics don't have the solution for this case.
When you mix normal columns with aggregate functions (for example SUM), you need to use GROUP BY where you list the normal columns from the SELECT.
The reason for the excessive amount in total_price for invoices is that the SUM is also calculated over each detail row as it is part of the join. Use this:
select c.id as customerID,
c.last_name,
c.first_name,
SUM(ci.total_price) as invoice_total,
SUM((select SUM(d.total_price)
from customer_invoice_details d
where d.customer_invoice_id = ci.id)) as 'detail_total_price'
from customers c
join customer_invoices ci on ci.customer_id = c.id
where c.id = 574413
group by c.id, c.last_name, c.first_name
db-fiddle
I used join against sub queries and then did a sum on the sums
SELECT c.id as customerID,
c.last_name,
c.first_name
SUM(i.sum) as invoice_total,
SUM(d.sum) AS details_total
FROM customers c
JOIN (SELECT id, customer_id, SUM(total_price) AS sum
FROM customer_invoices
GROUP BY id, customer_id) AS i ON i.customer_id = c.id
JOIN (SELECT customer_invoice_id as id, SUM(total_price) AS sum
FROM customer_invoice_details
GROUP BY customer_invoice_id) AS d ON d.id = i.id
WHERE c.id = 574413
GROUP BY c.id, c.name
The issue is in the joining logic. The table customers is used as the driving table in the joins. But in the second join, you are using a derivative key column from the first join, to join with the third tables. This is resulting in a Cartesian output doubling the records from the result from the nth-1 join, which is leading to customer_invoices.total_price getting repeated twice, hence the rolled up value of this field is doubled.
At a high level I feel that the purpose of rolling up the prices is already achieved in SUM(customer_invoice_details.total_price).
But if you have a specific project requirement that SUM(customer_invoices.total_price) should also be obtained and must match with SUM(customer_invoice_details.total_price), then you can do this:
In a separate query, Join customer_invoice_details and customer_invoices. Roll up the pricing fields, and have a result such that you have only one record for one customer ID.
Then use this as a sub-query and join it with the customers table.
You are aggregating along multiple dimensions. This is challenging. I would suggest doing the aggregation along each dimension independently:
select c.id as customerID, c.last_name, c.first_name,
ci.invoice_total,
cid.details_total
from customers c join
(select ci.sum(ci.total_price) as invoice_total
from customer_invoices ci
group by ci.customer_id
) ci
on ci.customer_id = c.id join
(select ci.sum(cid.total_price) as details_total
from customer_invoices ci join
customer_invoice_details cid
on cid.customer_invoice_id = ci.id
group by ci.customer_id
) cid
on cid.customer_id = c.id
where c.id = 574413;
A faster version (for one customer) uses correlated subqueries:
select c.id as customerID, c.last_name, c.first_name,
(select ci.customer_id, sum(ci.total_price) as invoice_total
from customer_invoices ci
where ci.customer_id = c.id
) as invoice_total,
(select ci.customer_id, sum(cid.total_price) as details_total
from customer_invoices ci join
customer_invoice_details cid
on cid.customer_invoice_id = ci.id
where ci.customer_id = c.id
) as details_total
from customers c
where c.id = 574413;

MySQL - Using subqueries on join and from

I am trying to return the CustomerID, CompanyName, OrderID, and subtotals for each customer for all order the subtotal amounts that are higher than the customer’s average subtotal amount. These are the tables I am using and the query below. I am unsure if the values I return are correct and was hoping someone could help me understand if they are or not based on my query. Thanks in advance.
Orders
Columns
OrderID
CustomerID
EmployeeID
OrderDate
RequiredDate
OrderDetails
Columns
OrderID
ProductID
UnitPrice
Quantity
Products
Columns
ProductID
ProductName
QuantityPerUnit
UnitPrice
Customers
Columns
CustomerID
CompanyName
ContactName
Country
SELECT A.CustomerID, A.CompanyName, A.Subtotal, A.OrderID, AVGSubtotal
FROM (
SELECT
C.CustomerID,
C.CompanyName,
(D.UnitPrice * P.QuantityPerUnit) AS Subtotal,
D.OrderID
FROM Customers C
JOIN Orders O ON C.CustomerID = O.CustomerID
JOIN OrderDetails D ON D.OrderID = O.OrderID
JOIN Products P ON P.ProductID = D.ProductID
GROUP BY
D.OrderID, C.CustomerID
) A
JOIN (
SELECT
S.CustomerID, S.CompanyName, AVG(S.Subtotal) as AVGSubtotal
FROM (
SELECT
C.CustomerID,
C.CompanyName,
(D.UnitPrice * P.QuantityPerUnit) AS Subtotal
FROM Customers C
JOIN Orders O ON C.CustomerID = O.CustomerID
JOIN OrderDetails D ON D.OrderID = O.OrderID
JOIN Products P ON P.ProductID = D.ProductID
GROUP BY
D.OrderID, C.CustomerID
) S
GROUP BY
S.CustomerID
) B ON A.CustomerID = B.CustomerID
WHERE
A.CustomerID = B.CustomerID AND
A.Subtotal > B.AVGSubtotal
ORDER BY
A.CustomerID, A.CompanyName
;
select
c2.customerID,
c2.CompanyName,
c2.AVGSubtotal
o2.OrderID,
o2.UnitPrice * o2.Quantity as subtotal
from (
select
c.CustomerID,
c.CompanyName,
sum(o.UnitPrice * o.Quantity)/count(*) as AVGSubtotal
from
Customers c
inner join Orders o on (o.CustomerID = c.CustomerID)
inner join OrderDetails od on (od.OrderID = c.OrderID)
group by
o.CustomerID
) as c2
inner join Orders o2 on (o2.CustomerID = c2.CustomerID)
where o2.UnitPrice * o2.Quantity > c2.AVGSubtotal

MySQL - Using subquery to find an average

I am having trouble with the syntax of this query. I am trying to return the largest total for one company from each country.
The tables look like:
Orders
Columns
OrderID
CustomerID
EmployeeID
OrderDate
RequiredDate
OrderDetails
Columns
OrderID
ProductID
UnitPrice
Quantity
Products
Columns
ProductID
ProductName
QuantityPerUnit
UnitPrice
Customers
Columns
CustomerID
CompanyName
ContactName
Country
I have tried the following:
SELECT
T1.Country,
CompanyName,
T1.OrderSum
FROM
(SELECT
C.Country,
C.CompanyName,
SUM(UnitPrice * Quantity) AS OrderSum
FROM Customers C
JOIN Orders O
ON C.CustomerID = O.CustomerID
JOIN OrderDetails D
ON D.OrderID = O.OrderID
GROUP BY C.Country) T1
JOIN
-- TOP PAYMENT TOTALS BY COUNTRY
(SELECT COUNTRY,
MAX(OrderSum) AS OrderSum
FROM
-- PAYMENT TOTALS BY CUSTOMER
(SELECT C.Country,
C.CompanyName,
SUM(UnitPrice * Quantity) AS OrderSum
FROM Customers C
JOIN Orders O1
ON O1.CustomerID = C.CustomerID
JOIN OrderDetails D1
ON D1.OrderID = O1.OrderID
GROUP BY C.COUNTRY, C.CompanyName) T2
GROUP BY COUNTRY) T3
ON T1.COUNTRY = T3.COUNTRY
AND T1.OrderSum = T3.OrderSum
ORDER BY Country;
This query only returns three countries:
Ireland Hungry Owl All-Night Grocers 57317.3900
Norway Sant Gourmet 5735.1500
Poland Wolski Zajazd 3531.9500
But, this query I tried, returns all countries, but I am not sure if it is correct because I did not include the 'max' value as I did in the previous query:
SELECT
T1.Country,
CompanyName,
T1.OrderSum
FROM
(SELECT
C.Country,
C.CompanyName,
SUM(UnitPrice * Quantity) AS OrderSum
FROM Customers C
JOIN Orders O
ON C.CustomerID = O.CustomerID
JOIN OrderDetails D
ON D.OrderID = O.OrderID
GROUP BY C.CompanyName) T1
GROUP By Country
ORDER BY Country;
I am also unsure if I am calculating the order totals correctly, which may be the mistake on my part. But I am trying to find the company from each country that has the largest order total.
Sorry for all the text.
The following query would list only the companies with the largest order total per country:
SELECT A.Country, A.CompanyName, A.OrderSum
FROM (
SELECT
C.Country,
C.CompanyName,
SUM(D.UnitPrice * D.Quantity) AS OrderSum
FROM Customers C
JOIN Orders O ON C.CustomerID = O.CustomerID
JOIN OrderDetails D ON D.OrderID = O.OrderID
GROUP BY
C.Country, C.CustomerID
) A
JOIN (
SELECT
S.Country, MAX(S.OrderSum) as MaxSum
FROM (
SELECT
C.Country,
C.CompanyName,
SUM(D.UnitPrice * D.Quantity) AS OrderSum
FROM Customers C
JOIN Orders O ON C.CustomerID = O.CustomerID
JOIN OrderDetails D ON D.OrderID = O.OrderID
GROUP BY
C.Country, C.CustomerID
) S
GROUP BY
S.Country
) B ON A.Country = B.Country
WHERE
A.Country = B.Country AND
A.OrderSum = B.MaxSum
ORDER BY
A.Country, A.CompanyName
;
[UPDATE]
Note that the above SQL follows the way OrderSum is calculated in your listed queries. Given that table Products has QuantityPerUnit and UnitPrice, I suspect that your OrderSum should be multiplied by QuantityPerUnit as well – in which case you'll need to revise the math for OrderSum.

SELECT a column and SUM() of values from another table in SQL

I'm pretty new with SQL, and this is giving me trouble. The idea is that I have several tables. Here are the relevant tables and columns:
customers:
customer_id, customer_name
orders:
order_id, customer_id
orderline:
order_id, item_id, order_qty
items:
item_id, unit_price
I need to return customer_name as well as total revenue from that customer (calculated as item_price * order_qty * 2).
Here's what I have written:
SELECT customers.customer_name, sum(revenue)
FROM SELECT orderline.order_qty * items.unit_value * 2 AS revenue
FROM orderline
INNER JOIN orders
ON orderline.order_id = orders.order_id
INNER JOIN customers
ON revenue.customer_id = customers.customer_id;
This throws a syntax error and I'm not really sure how to proceed.
This is only one example of this type of problem that I need to work out, so more generalized answers would be helpful.
Thanks in advance!
EDIT:
With help from answers I ended up with this code, which just gets total revenue and puts it next to the first person in the DB's name. What did I get wrong here?
SELECT customers.customer_name, sum(revenue)
FROM(SELECT orderline.order_qty * items.unit_price * 2 AS revenue, orders.customer_id AS CustomerID
FROM( orderline
INNER JOIN orders
ON orderline.order_id = orders.order_id
INNER JOIN items
ON orderline.item_id = items.item_id)) CustomerOrders
INNER JOIN customers
ON CustomerOrders.CustomerID = customers.customer_id;
A couple issues with your query.
First, you need to scope your subquery and alias it:
(SELECT orderline.order_qty * items.unit_value * 2 AS revenue
FROM orderline
INNER JOIN orders
ON orderline.order_id = orders.order_id) CustomerOrders
Secondly, you need to select more than the revenue in the subquery since you are joining it to your customers table
(SELECT
orderline.order_qty * items.unit_value * 2 AS revenue,
orders.customer_id AS CustomerId
FROM
orderline
INNER JOIN orders ON orderline.order_id = orders.order_id) CustomerOrders
Then you need to use the subquery alias in the join to the customers table and wrap it all up in a group by customer_id and CustomerOrders.Revenue
I would tend to do it differently. I'd start with selecting from the customer table, because that is the base of what you are looking for. Then I'd do a cross apply on the orders that would all aggregating the order revenue in the subquery. It would look like this (tsql, you could do the same in mysql with a join with some aggregation):
SELECT
customers.customer_name,
ISNULL(customerOrders.Revenue, 0) AS Revenue
FROM
customers
OUTER APPLY (
SELECT
SUM (orderline.order_qty * items.unit_value * 2) AS Revenue
FROM
orders
INNER JOIN
orderline ON orders.order_id = orderline.order_id
INNER JOIN
items on orderline.item_id = items.item_id
WHERE
orders.customer_id = customers.customer_id
) CustomerOrders
In this case, the subquery aggregates all your orders for you and only returns one row per customer, so no extraneous returned data. Since it's an outer apply, it will also return null for customers with no orders. You could change it to a CROSS APPLY and it will filter out customers with no orders (like an INNER JOIN).
SELECT c.customer_name,
sum(COALESCE(ol.order_qty,0) * COALESCE(i.unit_value,0) * 2)
FROM customers c
INNER JOIN orders o
ON o.customer_id = c.customer_id;
INNER JOIN orderline ol
ON ol.order_id = o.order_id
INNER JOIN items i
ON i.item_id = ol.item_id
GROUP BY c.customer_id
select customer_name, sum(item_price * order_qty * 2) as total_revenue
from (
select * from customers
inner join orders using(customer_id)
inner join orderline using(order_id)
inner join items using(item_id)
)
group by customer_name
select
c.customer_name,
r.revenue
from
customers c
inner join
orders ord on
ord.customer_id = c.customer_id
inner join
(select i.item_id, o.order_id, sum(o.order_qty * items.unit_value * 2) as revenue
from orderline o
inner join items i on
i.item_id = o.item_id
group by o.order_id, i.item_id) as r on r.order_id = o.order_id