i am having problems using an inner join for 3 tables..
i need to display cust_id, the customer forename and surname, the product name<-(from products table) and date of sale<--(from sales table), also i need to display in order of the most recent dates first.
this is what i have got so far
enter SELECT
customers.cust_id,
customers.forename,
customers.surname,
products.prod_name,
sales.Date_of_sale
FROM
customers
INNER JOIN
sales
ON
customers.cust_id = sales.cust_id; here
id really appreciate it if you could help me here, thank you..
Just add one more JOIN to the products table and include an ORDER BY clause:
SELECT
c.cust_id,
c.forename,
c.surname,
p.prod_name,
s.Date_of_sale
FROM customers c
INNER JOIN sales s ON c.cust_id = s.cust_id
INNER JOIN products p ON s.product_id = p.product_id
ORDER BY s.Date_of_sale DESC
A Visual Explanation of SQL Joins
I think the problem is in your FROM parameter.
You specified only customer.
SELECT customers.cust_id, customers.forename, customers.surname, products.prod_name, sales.Date_of_sale
FROM
customers , products , sales
INNER JOIN
sales
ON
customers.cust_id = sales.cust_id;
Related
first sorry, i don't have fluid english.
I want select 3 rows in 3 different tables, two of them without Foreing Key/relation.
Need to select amount of customers in each store, and total amount of payments in these stores in one query.
Here are the tables:
Customers
Stores
Payments
I have tried these querys to get payments for each store and customers for each store, but don't know how can unify in one query:
Payments/store
SELECT count(a.payment_id) as alquileres, b.store_id
FROM customer b, payment a
WHERE a.customer_id = b.customer_id
GROUP BY b.store_id;
customers/store
SELECT count(customer_id), store_id
FROM customer
GROUP BY store_id;
But when I add count(customer_id) in unique query don't have same results.
You can use one query:
select c.store_id,
count(distinct c.customer_id) as num_customers,
count(p.payment_id) as num_payments
from customers c left join
payments p
on p.customer_id = c.customer_id
group by c.store_id;
I have the following three tables:
I have Following Query to Join Above 3 Tables
customer.customer_id,
customer.name,
SUM(sales.total),
sales.created_at,
SUM(sales_payments.amount)
FROM
sales INNER JOIN customer ON customer.customer_id = sales.customer_id
INNER JOIN sales_payments ON sales.customer_id = sales_payments.customer_id
WHERE sales.created_at ='2020-04-03'
GROUP By customer.name
Result for Above Query is given below
Sum of sales.total is double of the actual sum of sales.total column which has 2-row count, I need to have the actual SUM of that column, without doubling the SUM of those rows, Thank you, for your help in advance..
PROBLEM
The problem here is that there are consecutive inner joins and the number of rows getting fetched in the second inner join is not restricted. So, as we have not added a condition on sales_payment_id in the join between the sales and sales_payment tables, one row in sales table(for customer_id 2, in this case) would be mapped to 2 rows in the payment table. This causes the same values to be reconsidered.
In other words, the mapping for customer_id 2 between the 3 tables is 1:1:2 rather than 1:1:1.
SOLUTION
Solution 1 : As mentioned by Gordon, you could first aggregate the amount values of the sales_payments table and then aggregate the values in sales table.
Solution 2 : Alternatively (IMHO a better approach), you could add a foreign key between sales and sales_payment tables. For example, the sales_payment_id column of sales_payment table can be introduced in the sales table as well. This would facilitate the join between these tables and reduce additional overheads while querying data.
The query would then look like:
`SELECT c.customer_id,
c.name,
SUM(s.total),
s.created_at,
SUM(sp.amount)
FROM customer c
INNER JOIN sales s
ON c.customer_id = s.customer_id
INNER JOIN sales_payments sp
ON c.customer_id = sp.customer_id
AND s.sales_payments_id = sp.sales_payments_id
WHERE s.created_at ='2020-04-03'
GROUP BY c.customer_id,
c.name,
s.created_at ;`
Hope that helps!
You have multiple rows for sales_payments and sales per customer. You need to pre-aggregate to get the right value:
SELECT c.customer_id, c.name, s.created_at, s.total, sp.amount
FROM customer c JOIN
(SELECT s.customer_id, s.created_at, SUM(s.total) as total
FROM sales s
WHERE s.created_at ='2020-04-03'
GROUP BY s.customer_id, s.created_at
) s
ON c.customer_id = s.customer_id JOIN
(SELECT sp.customer_id, SUM(sp.amount) as amount
FROM sales_payments sp
GROUP BY sp.customer_id
) sp
ON s.customer_id = sp.customer_id
hi, I have a problem with MySQL.
I want to group by records based on latest records
I designed my tables and desire result in above image
please help me. thanks
You can get latest (inserted_date) for every PID then use that as separate table.
Eg:
SELECT P.PID, S.SID, P.PRODUCTNAME, S.PRICE, S.COUNT, S.INSERTED_DT FROM
PRODUCT P
INNER JOIN
(
SELECT PID, MAX(INSERTED_DATE) AS LATEST_DT FROM STOCK
) P1 ON P.PID = P1.PID
INNER JOIN STOCK S ON S.PID = P.PID AND S.INSERTED_DATE = P1.LATEST_DT
I have a table containing customers and another containing all orders.
I want to display a list of customers and along side show the total value of their orders.
Obviously I could loop through the customers and then using PHP run another query to get each customer's revenue. I don't think this is efficient.
I am looking to achieve something like this:
SELECT username, [SELCT sum(revenue) from orders where userID=userID] from customers
And for this to show output:
bob 10000
jeff 25000
alan 500
SELECT a.username, SUM(b.revenue) totalRevenue
FROM customers a
LEFT JOIN Orders b
ON a.userID = b.UserID
GROUP BY a.username
This will list all customers with or without Orders.
To further learn more about join, please visit the article below,
Visual Representation of SQL Joins
you're close...
SELECT username, (SELECT sum(revenue) from orders where userID=c.userID) rev
from customers c
You can join the tables and the group them by the order name
SELECT o.username,
sum(revenue) as sum_revenue
from orders o
left outer join customers c on c.userid = o.userid
group by o.username
No need for a subselect with that. Try something like this:-
SELECT customers.userID, customers.username, SUM(revenue)
FROM customers INNER JOIN orders ON customers.userID = orders.userID
GROUP BY customers.userID, customers.username
This is a part of SQL coding project of database.
I need to design a single table to hold orders made by customers.
Assume that customers' details (e.g. names) are stored in another table.
Using the table that I designed for orders, and this assumed other table, write
a single SQL query that can give the number of orders for every customer, one line per customer.
The “Orders” table
Order_ID Order_NO Customer_ID
1 8088 3
2 9632 1
3 1272 4
4 6037 1
Assume that the customer names and other details (address, phone numbers, emails) are stored in the “Customers” table.
My SQL:
SELECT Customers.FirstName, Customers.FirstName, Orders.OrderNo
FROM Customers
FULL JOIN Orders
ON Customers.Customer_ID = Orders.Customer_ID
ORDER BY Customers.LastName
Are there something wring with it ?
Change the query to inner join
SELECT
Customers.FirstName
, Customers.FirstName
, Orders.OrderNo
FROM
Customers
INNER JOIN Orders ON Customers.Customer_ID = Orders.Customer_ID
ORDER BY
Customers.LastName
Query for Ordercount for customer
SELECT
Customers.LastName
, COUNT(Orders.Order_Id)
FROM
Customers
INNER JOIN Orders ON Customers.Customer_ID = Orders.Customer_ID
GROUP BY
Customers.LastName
ORDER BY
Customers.LastName
Full join
http://www.w3schools.com/sql/sql_join_full.asp
Inner join
http://www.w3schools.com/sql/sql_join_inner.asp
If you just want to COUNT the orders you can do this:
SELECT
Customers.FirstName,
(
SELECT
COUNT(*)
FROM
Orders
WHERE
Orders.Customer_ID=Customers.Customer_ID
) AS NbrOfOrders
FROM
Customers
References:
12.15.1. GROUP BY (Aggregate) Functions
Don't forget COUNT and GROUP BY.