I have some problem with the query issue when trying to sum up the quantity.
Table
This cart item table stored id_cart and id product
This order table stored id_cart and other id may be included such as supplier. This table is used to track order record and send notification to supplier.
Wrong result. Expected output = 1, 1, 1
SELECT id, id_product, SUM(qty)
from cart_item
left join Orderp using(id_cart)
group by id_product
http://sqlfiddle.com/#!9/07bf57/1
The issue caused by duplicate id_cart in order table as well. How can i handle this? Any solution to make it works? Thanks.
There is something wrong in your data, or in your data model
INSERT INTO OrderP(`id_order`,`id_cart`)VALUES(1, 1);
INSERT INTO OrderP(`id_order`,`id_cart`)VALUES(2, 1);
There are 2 rows for id_cart = 1, so the "natural join" will double every row when joining cart_item to orderp.
Using an inner join to a different column in orderp works better because now there is only one row in orederp for each cart_item.
SELECT id_product, sum(qty)
from cart_item ci
left join Orderp o on ci.id_cart = o.id_order
GROUP BY id_product
http://sqlfiddle.com/#!9/07bf57/13
Try the following query
SELECT
i.id_product,
p.name productname,
b.id_branch,
b.branchname,
SUM(i.qty)
from cart_item i
left join (SELECT DISTINCT id_cart,id_branch FROM Orderp) o on o.id_cart=i.id_cart
left join product p on i.id_product=p.id_product
left join catalog c on c.id_product=p.id_product and c.id_branch=o.id_branch
left join branch b on b.id_branch=o.id_branch
group by
i.id_product,
p.name,
b.id_branch,
b.branchname
The main problem in Orderp table because it containts two different orders for one cart (DISTINCT id_cart,id_branch helps here). And you need to use the second condition by id_branch for catalog (and c.id_branch=o.id_branch).
SQL Fiddle - http://sqlfiddle.com/#!9/f32d5f/16
And I think you can use everywhere INNER JOIN instead LEFT JOIN
SELECT
i.id_product,
p.name productname,
b.id_branch,
b.branchname,
SUM(i.qty)
from cart_item i
join (SELECT DISTINCT id_cart,id_branch FROM Orderp) o on o.id_cart=i.id_cart
join product p on i.id_product=p.id_product
join catalog c on c.id_product=p.id_product and c.id_branch=o.id_branch
join branch b on b.id_branch=o.id_branch
group by
i.id_product,
p.name,
b.id_branch,
b.branchname
Related
I have three tables as below, each product may belong to multiple categories.
PRODUCT TABLE AS P
1. ID
2. NAME
CATEGORY TABLE AS C
1. ID
2. NAME
RELATION TABLE AS R
1. ID
2. P_ID
3. C_ID
Now I want to get a list of all products in product table, and with their belonging category name display as well.
How do I write this query?
I can get the category ids pulled from the same query, but don't know how to get all the name pulled as well. Here's what I tried.
select p.*,y.*
from p
left join (select p_id,group_concat(c_id) as category_ids
from relation group by p_id) as y on p.id=y.p_id
Do both JOIN operations (to the relation table, and from there to the table containing the category names) and feed the result to your aggregation function (GROUP_CONCAT)
SELECT P.Name, GROUP_CONCAT(DISTINCT C.Name ORDER BY C.Name SEPARATOR '|') categories
FROM Product P
LEFT JOIN Relation R ON P.ID = R.P_ID
LEFT JOIN Category C ON R.C_ID = C.ID
GROUP BY P.ID, P.Name
This will give you one row per product with the categories separated by |.
This uses LEFT JOIN operations so it won't suppress products that have no categories.
Select P.Name, C.Name
From RELATION R Inner Join PRODUCT P
On R.P_ID=P.Id
Inner Join Category C
On C.Id=R.C_ID
This query will get you all the products, with their corresponding category.
I want to give you a small explanation about the difference between Inner Join and Left Join.
If we take as an example 2 tables :
TA(idA, description) and TB(idB, idA, description).
Select TA.description, TB.description
From TA Inner Join TB On TA.IdA = TB.IdA
will get only the rows in TA, that have a corresponding one in TB.
On the other side,
Select TA.description, TB.description
From TA Left Join TB On TA.IdA = TB.IdA
will get all the rows of TA and if the row in TA doesn't have a corresponding one in TB, TB.description for this row will be NULL.
Hope this helps!
I'm trying to create a view of some columns from 3 different tables. One of the columns 'OrderNumber' is in 2 of the tables so I'm trying to do a UNION for them, but because I've made a subquery it returns an 1242 error and won't return more than 1 row. I just want to know how I can rewrite this query so that there are no subqueries, or is there someway to bypass it. Or perhaps I need to write multiple queries? Though I'd prefer to keep it to the one query, thanks.
CREATE VIEW CustOrderItems AS
SELECT CustFirstName,
CustLastName,
(SELECT OrderNumber
FROM Orders
UNION
SELECT OrderNumber
FROM Order_Details)
OrderDate,
ShipDate,
QuantityOrdered * QuotedPrice as ItemTotal
FROM Customers JOIN Orders JOIN Order_Details;
Substitute whatever your customer id
drop view if exists custorders;
create view custorders as
SELECT c.CustFirstName,
c.CustLastName,
o.OrderNumber order_ordernumber,
od.OrderNumber orderdetails_ordernumber,
o.OrderDate,
o.ShipDate,
od.QuantityOrdered * od.QuotedPrice as ItemTotal
FROM Customers c
JOIN Orders o on c.id = o.cust_id
JOIN Order_Details od on o.ordernumber = od.ordernumber
where c.id = ?
It's not clear what are your join criteria because the statement syntax is bad. But I assume you want to join on OrderNumber like SELECT ... FROM Customers INNER JOIN Orders ON Customers.OrderNumber = Orders.OrderNumber. In this case, if you want to use order numbers from two tables just repeat the query and make union of the two like:
SELECT ,,, FROM Customers INNER JOIN Order_Details ON Customers.OrderNumber = Order_Details.OrderNumber
UNION
SELECT FROM Customers INNER JOIN Orders ON Customers.OrderNumber = Orders.OrderNumber
I'm following the SQL tutorial from w3schools.
I want to get the value of all orders delivered by a shipper. I don't have any idea about how I can get these details as the info are in different tables and the INNER JOIN didn't worked for me.
Database: http://www.w3schools.com/sql/trysql.asp?filename=trysql_select_groupby
By now, I managed to get the number of orders by each shipper.
SELECT Shippers.ShipperName,COUNT(Orders.OrderID) AS NumberOfOrders FROM Orders
LEFT JOIN Shippers
ON Orders.ShipperID=Shippers.ShipperID
GROUP BY ShipperName;
How could I get the value of those?
To bring the Price of a Product into your query you will need to join in tables OrderDetails to the Order table on the Orders.Id and then join in the Products table to the OrderDetail table on ProductID
SELECT Shippers.ShipperName,
COUNT(Orders.OrderID) AS NumberOfOrders,
Sum(Products.price * OrderDetails.Quantity) AS SumOfPrice
FROM Orders
LEFT JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID
LEFT JOIN OrderDetails ON ORders.OrderID = OrderDetails.OrderID
LEFT JOIN Products ON OrderDetails.ProductID = Products.ProductID
GROUP BY ShipperName;
I just stuck with LEFT JOIN here as your example used, but an INNER JOIN would work just as well and be more efficient.
The FROM clause of the SQL statement is one of the first parts of the SQL to run against your database. It establishes which tables we are grabbing information from and the relationship between those tables (using the ON keyword). So here we bring in 4 tables, and use the ON keyword to show the relationship between all of them using their respective IDs. Then we can add their fields to the SELECT portion of the SQL statement and aggregate where needed.
If you want the "sum" of the product prices, that would be very similar to what you already have. Note how you currently use the COUNT() function to get the count, you can use the SUM() function to get the total of any numeric column.
Something like this:
SELECT
Shippers.ShipperName,
COUNT(Orders.OrderID) AS NumberOfOrders,
SUM(Products.Price) AS PriceOfOrders
FROM
Orders
INNER JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID
INNER JOIN OrderDetails ON Orders.OrderID = OrderDetails.OrderID
INNER JOIN Products ON OrderDetails.ProductID = Products.ProductID
GROUP BY
ShipperName
Or perhaps the price also needs to be multiplied by the quantity in this calculation? Something like this:
SELECT
Shippers.ShipperName,
COUNT(Orders.OrderID) AS NumberOfOrders,
SUM(Products.Price * OrderDetails.Quantity) AS PriceOfOrders
FROM
Orders
INNER JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID
INNER JOIN OrderDetails ON Orders.OrderID = OrderDetails.OrderID
INNER JOIN Products ON OrderDetails.ProductID = Products.ProductID
GROUP BY
ShipperName
It's up to your understanding of the table structure and the data, really. But the concept is the same, grouping by a value and applying a calculation to the grouped values (count or sum).
Select distinct is returning indistinct rows. Why?
I want to return distinct shops.
Here is my sql statement:
SELECT
DISTINCT s.*, p.p_id
FROM
shop s
INNER JOIN product_shop ps on s.s_id = ps.s_id
INNER JOIN product p ON p.p_id = ps.p_id
WHERE
s.country = 'new zealand'
Here is the result:
The product (p.p_id) needs to not be distinct, as I want to return a list of shops that have a specific product. But the Shop needs to be distinct.
What am I doing wrong?
Returned rows are distinct. Distinct is applied to all returned row, not to single column. Yes, p_id is same for two rows. But if you compare all columns, there are differences between them.
If you want distinct shops - don't include in select columns from other tables, because it can cause duplicates as in your example.
Simply don't include p.p_id within your selection.
I.e.
SELECT DISTINCT
s.*
FROM shop s
....
Well, If you will look at your entire output, you can see the p_id(the last column) is different for each row. Distinct applies to the entire record, not just one column.
You can either drop the p_id from your select, or use group by and decide which one of the p_id you want, perhaps max? :
SELECT
s.*, max(p.p_id)
FROM
shop s
INNER JOIN product_shop ps on s.s_id = ps.s_id
INNER JOIN product p ON p.p_id = ps.p_id
WHERE
s.country = 'new zealand'
GROUP BY s.id
Here is my tables:
Book (id ,title ,author ,isbn ,cost)
Orders(orderID ,orderDate ,user(manyToOne) ,orderItems(oneToMany))
OrderItem(id ,book(ManyToOne) ,quantity ,totalPrice)
this is the query:
And here is the result:
But, the result should had just 2 rows, contain just orderId 1 and 2 not 4 rows.
You are not joining on order correctly. It looks like it is doing a cross join. See the correct sql below.
select
*
from
orders o
inner join orderitem oi on
oi.orderID = o.orderID -- note the additional join here
inner join book b on
b.id = oi.book_id
You can see on the join I have joined orders onto orderitem correctly. You might need to change the id since I am not sure if it should be order_id, orderID or just ID. Don't know your schema.