I am trying to learn joins with many to many relationships in mysql,
I have four tables:
customers, orders, products, payments
I am trying to get records as:
customer_name, order_status, pay_method, pro_name
the query I use:
SELECT cust_name,order_status,pay_method,pro_name FROM customer
INNER JOIN orders ON customer.cust_id = orders.cust_id
INNER JOIN payments ON payments.order_id = orders.order_id
INNER JOIN products ON products.pro_id = orders.pro_id
I am receiving results as I want with no issue. But this query shows only one product against one order, then I realize I should have another separate table which will hold many products against one order. In this issue I am not able to get desired result
It's not entirely clear what you're asking, but I'm guessing what you're trying to do is create a many to many table that links orders and products? In which case, you can just create a table called "productorders" which will contain an order_id and a pro_id. Then you would modify your query like this:
SELECT cust_name,order_status,pay_method,pro_name FROM customer
INNER JOIN orders ON customer.cust_id = orders.cust_id
INNER JOIN payments ON payments.order_id = orders.order_id
INNER JOIN productorders ON productorders.order_id = orders.order_id
INNER JOIN products ON products.pro_id = productorders.pro_id;
Joining productorders will get all products associated with an order, and then joining products will get the information associated with each product.
Related
I have 5 tables that need to be joined. These tables have to do with orders placed by customers and the orders turned into purchase orders for the relevant suppliers.
Table product_sale holds the customers products that they've ordered.
Table product holds the main information on those products.
Table sale_purchase is a bridging table between the sale and purchase order.
Note: This may or may not exist as the product might be out of stock and no purchase order was required.
Table product_purchase holds those linked products on the purchase order.
Table grn handles the receiving of those products.
Unfortunately in the customers sales order, I will need to access information from all of these tables. Here's the query I have so far:
SELECT
ps.*,
pp.received_qty,
p.group_ref,
p.subgroup_ref,
g.grn_id AS 'grn_ref',
g.grn_date
FROM
product_sale ps
INNER JOIN product p ON ps.product_ref = p.product_id
LEFT JOIN sale_purchase sp ON ps.sale_ref = sp.sale_ref
LEFT JOIN product_purchase pp ON pp.so_line_no = ps.line_no
LEFT JOIN grn g ON g.grn_id = pp.grn_ref
WHERE
ps.sale_ref = 150002
GROUP BY
line_no
ORDER BY
line_no
So far so good, although the received_qty for one line is wrong:
The first line's received qty should be 7 and not 4. I've checked the grn table and it definitely says 7. Can I please get some help as to where I am going wrong with this query? Also the grn_ref and grn_date should be NULL for line_no 1.00
Scrap it guys. I figured it out. I hadn't accounted for another purchase order that was in the system. Solution to the problem was adding AND pp.purchase_ref = sp.purchase_ref to the left join for product_purchase. See revised code below:
SELECT
ps.*,
pp.received_qty,
p.group_ref,
p.subgroup_ref,
g.grn_id AS 'grn_ref',
g.grn_date
FROM
product_sale ps
INNER JOIN product p ON ps.product_ref = p.product_id
LEFT JOIN sale_purchase sp ON ps.sale_ref = sp.sale_ref
LEFT JOIN product_purchase pp ON pp.so_line_no = ps.line_no AND pp.purchase_ref = sp.purchase_ref
LEFT JOIN grn g ON g.grn_id = pp.grn_ref
WHERE
ps.sale_ref = 150002
GROUP BY
line_no
ORDER BY
line_no
I believe I have formed this question title correctly because I wasn't sure how to form it. As an example, I have summarized my query below.
I have an order table which saves order details like customer id, address and product ids and quantity ordered for each order in a row. So multiple inventory/product ids are saved in a single row.
so my query looks like: this is a summarized query for an easier explanation I have omitted various other fields.
SELECT customer.name,customer.address,tbl_order.order_date,tbl_order.product1_id,tbl_order.product2_id,inventory.product1_name,inventory.product2_name
FROM tbl_order
INNER JOIN customer ON tbl_order.customer_id = customer.id
INNER JOIN inventory on tbl_order.product1_id = inventory.id
INNER JOIN inventory on tbl_order.product2_id = inventory.id
where YEAR(tbl_order.order_date)='$year'
So my question is how to get the inventory details from the inventory table based on each product id from tbl_order. I am running a while loop to show all data for a year
while($row=mysqli_fetch_assoc($sql1))
I can divide this query into 2 and run the inventory query individually but then how to combine the while loop, as sometimes there could also be empty query when some products are not in order table (depending on order to order, not all products are ordered) so this doesn't work
while($row=mysqli_fetch_assoc($sql1)) and ($row1=mysqli_fetch_assoc($inv1)) and ($row2=mysqli_fetch_assoc($inv2))
and so one for 10 products
First, of all you have bad DB design and I kindly advice to normalize your DB.
Second, if you can not re-design the DB you can use multiple joins with aliases like:
SELECT
customer.name, customer.address, tbl_order.order_date,
tbl_order.product1_id, inv1.product1_name,
tbl_order.product2_id, inv2.product2_name
FROM tbl_order
INNER JOIN customer ON tbl_order.customer_id = customer.id
INNER JOIN inventory AS inv1 ON tbl_order.product1_id = inv1.id
INNER JOIN inventory AS inv2 ON tbl_order.product2_id = inv2.id
WHERE YEAR(tbl_order.order_date)='$year'
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).
I have four tables orders, items, projects, and stores. I would like to join them together.
This is my orders table:
My expected result will look like this:
Also this is my naked query without join.
SELECT orders.ID,orders.Quantity, items.Desc, stores.store_name, projects.Project_no
FROM orders, items, stores, projects
You need to use a join on the primary keys and foreign keys of other table.
for eg.
SELECT orders.ID,orders.Quantity, items.Desc, stores.store_name, projects.Project_no
FROM orders
join items ON (orders.orderId = items.orderid)
join stores ON (items.storeID = store.storeID)
join projects ON (projects.projectId = store.projectId)
Note : this is assume some primary keys.
Assuming the ID columns are named the same in the other tables,
SELECT orders.ID, orders.Quantity, items.Desc, stores.store_name, projects.Project_no
FROM orders
join items on items.item_id=orders.item_id
join stores on stores.store_id=orders.store_id
join projects on projects.project_id=orders.project_id
SELECT orders.ID,orders.Quantity, items.Desc, stores.store_name, projects.Project_no FROM orders o
inner join items on items.item_id - o.item_id
inner join stores on stores.store_id = o.store_id
inner join Projects on projects.project_id = o.project_id
This should work, however i have made assumptions about your id columns in your additional tables.
I have three tables in MySQL.
customers which has columns {id, name, and email}
products which has columns {id and name}
purchased which contains {id, customer}
product where customer and product are indexes of customers.id and products.id respectively.
I am a little confused on how to get the customer's name and all products he has purchased. Here is what I have and it is basically returning all possible combinations of products and customers instead of the specific customers info:
SELECT
customers.email,
products.name
FROM
customers, products, purchased
INNER JOIN
customers cu
ON
cu.id = purchased.customer
INNER JOIN
products pr
ON
pr.id = purchased.product
WHERE
purchased.customer = 1
I expect this to return all products purchased by a customer with ID of 1 but it is not. Can someone help me here?
You are mixing the explicit and implicit join and hence creating the issue.
You may have the query as below. In addition you have used alias for the joining tables and need to use them in the select as well.
SELECT cu.email, pr.name FROM purchased
INNER JOIN customers cu
ON cu.id = purchased.customer
INNER JOIN products pr
ON pr.id = purchased.product
WHERE pr.customer = 1