mysql right join multiple tables - mysql

I’m new to mySQL and I’m struggling to write a query that will list all stores where a price for a product has been scanned as well as the stores where it has not been scanned. The following gives the correct result for a single product:
select distinct(s.id) as store_id, s.chainID as chain_id, p1.productID as product_id,
s.chain, s.location, s.city, prd.brand, prd.product, prd.quantity, prd.size, prd.unit
from analytics.price p1 -- Fact table with prices
join analytics.pricetime pt -- Dimension table with time a price was scanned
on p1.priceTimeID = pt.id
join analytics.product prd -- Dimension table with products
on p1.productID = prd.id
and prd.published = 1
right join analytics.store s -- Dimension table with stores and the chain they belong to
on p1.storeID = s.id
and p1.chainID = s.chainID
and p1.productID = 46720
and p1.priceTimeID between 2252 and 2265
where s.published=1
and s.chainID = 5;
When I remove the p1.productID = 46720 clause to get results for all products, I get all the stores that have scanned prices (correct), but the no price side of the right join only shows stores that have not had any prices scanned for any products. (This is a simple star schema with a price fact and dimensions of product, time and store). I would greatly appreciate help – I’ve tried this every way I can think of including “in”, “not exists” and stored procedure with cursor but I seem to hit a brick wall each way I try it.
Edited to clarify:
Here's what I'm trying to achieve:
Price table
Product Chain Store Price
100 5 1 $10
101 5 2 $20
Store table
Chain Store
5 1
5 2
5 3
Desired Result
Product Chain Store Price
100 5 1 $10
100 5 2 NULL
100 5 3 NULL
101 5 1 NULL
101 5 2 $20
101 5 3 NULL
Actual Result
Product Chain Store Price
100 5 1 $10
101 5 2 $20
NULL 5 3 NULL

I prefer the readability of using a LEFT JOIN -- this should return all published stores in chainid 5 and the associated products (given the criteria).
select distinct s.id as store_id, s.chainID as chain_id, s.chain, s.location, s.city,
prd.id as product_id, prd.brand, prd.product, prd.quantity, prd.size, prd.unit
from analytics.store s
left join analytics.price p1
on p1.storeID = s.id
and p1.chainID = s.chainID
and p1.priceTimeID between 2252 and 2265
left join analytics.product prd
on p1.productID = prd.id
and prd.published = 1
left join analytics.pricetime pt
on p1.priceTimeID = pt.id
where s.published=1
and s.chainID=5;
EDIT -- Give comments, it looks like you're looking for a Cartesian Product:
SELECT P.Product, P.Chain, S.Store, IF(P.Store=S.Store,P.Price,NULL) Price
FROM Price P, Store S
WHERE P.Chain = 5
AND S.Chain = P.Chain
ORDER BY P.Product, S.Store
SQL Fiddle Demo

Related

MySQL How to get the row with max date when joining multiple tables?

My goal is the get a list of current prices and prices at the time of whatever date is given. The price as of today is always product.price. Each time a new price is set, an entry is added to product_audit and revinfo.
If we are looking for what the prices were on 2020-11-31, it would return:
num CurrentPrice OldPrice
--------------------------------------
1001 100 175
1030 110 100
2010 150 130
EDIT FOR CLARIFICATION: My intention is to get what the price was on a specific day. So OldPrice is actually the newest entry in Product_aud/revinfo that is before or on the set date (in this case, 2020-11-31). Looking specifically at code 1001, the price was changed on 2020-08-02, 2020-09-26, and 2020-01-08. If we are looking at 2020-11-31, that means it should grab 2020-09-26 because it is the soonest date before then. This means the price of 1001 on 2020-11-31 was 175.
There are three tables: Product, product_audit, revinfo
Everytime the price is changed, an entry is added to product_audit with the new price and a reference to a new entry in revinfo that has the date/time. Revinfo contains entries for other audit tables mixed in.
product.id = product_audit.id
product_audit.rev = revinfo.id
product
id num price
------------------------
1 1001 100
2 1030 110
3 2010 150
product_audit
id rev price
------------------------
1 1 200
1 3 175
1 6 100
2 2 100
2 7 110
3 4 130
3 5 120
3 8 150
revinfo
id timestamp
-------------------
1 2020-08-02
2 2020-09-25
3 2020-09-26
4 2020-11-12
5 2020-12-20
6 2021-01-08
7 2021-01-09
8 2021-01-23
Of course this just returns the oldest price from product_audit:
SELECT product.num, product.price AS CurrentPrice, product_audit.price AS OldPrice
FROM product
LEFT JOIN product_audit ON product_audit.id = product.id
LEFT JOIN revinfo ON revinfo.id = product_audit.rev
WHERE rev.timestamp <= "2020-11-31"
GROUP BY product.id
I tried nesting joins like this based on some stuff I was reading, but quickly realized it still wasn't going to get the right price:
SELECT product.id, product.num, product.price AS CurrentPrice, revisions.price AS OldPrice
FROM product
LEFT JOIN (SELECT product_audit.id AS id, product_audit.price AS price, MAX(revinfo.timestamp) AS timestamp
FROM product_audit
LEFT JOIN revinfo ON product_audit.rev = revinfo.id
WHERE revinfo.timestamp <= $DATE{Date}
GROUP BY product_aud.id) AS revisions ON revisions.id = product.id
I can't seem to think of how to get to that last step. Some sort of WHERE timestamp = (SELECT...) maybe? But I haven't been able to figure that out.
Also, just a heads up, I'm limited to statements that start with SELECT because of permissions. I can't add functions or anything like that.
I had to assume how we were getting the "old" price, and my assumption was that you wanted the "earliest" revision record, so I used Row_number and a derived table to get that record and then use it in the join constraint for the revision table... not exactly sure what your logic is, but here is a fiddle with the resultset that matches your "desired results"
SELECT product.num, product.price AS CurrentPrice, product_audit.price AS OldPrice
FROM product
LEFT JOIN (select p.price, p.id, p.rev,
ROW_NUMBER() over (partition by p.id order by p.rev asc) as rn
From product_audit p
) AS product_audit ON product_audit.id = product.id
and product_audit.rn = 1
LEFT JOIN revinfo ON revinfo.id = product_audit.rev
WHERE revinfo.timestamp <= '2020-11-31';
https://www.db-fiddle.com/f/fbvrgo2gRLoBPhgwQnuvY9/3
WITH cte AS ( SELECT product.num,
product.price CurrentPrice,
product_audit.price OldPrice,
ROW_NUMBER() OVER (PARTITION BY product.num
ORDER BY revinfo.`timestamp` DESC) rn
FROM product
JOIN product_audit ON product_audit.id = product.id
JOIN revinfo ON revinfo.id = product_audit.rev
WHERE revinfo.`timestamp` <= #date
)
SELECT num, CurrentPrice, OldPrice
FROM cte
WHERE rn = 1;
https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=a276ec8ad89e3c2f3aaeee411072fa3e

SQL task if the product has no sales in the given month, then display 0 in this month

I have to build and SQL query which must do these things:
select all products from table "products" - satisfied
SUM all sales and forecast to the next 3 months - satisfied
check if the product has no one sale, then write "0" -> here is the problem, because I don't know how to do that..
My SQL query is here..
select product.name,
(select sum(amount)
from forecast
where forecast.product_id = product.id),
sum(sale.amount)
from product join
 sale
  on sale.product_id = product.id
where sale.outlook > -4
group by product.id
Here is the products table:
id name
1 milk
2 roll
3 ham
Table sale (same structure like forecast):
product_id outlook amount
1 -1 9
1 -2 13
1 -3 14
2 -1 88
2 -3 61
3 -1 33
3 -4 16
You can use left join to bring in the rows and coalesce() to get the 0 instead of NULL:
select p.name,
(select sum(f.amount)
from forecast f
where v.product_id = p.id),
coalesce(sum(s.amount), 0)
from product p left join
sale s
on sale.product_id = product.id and
sale.outlook > -4
group by p.id
Understand the requirement to be, show the sales per product and if no sale for a product show "0". Tables are named Products and Sale.
For this, "with" statements are useful and help understanding too:
With SalesSummary as
(
select product_id, sum(amount) as ProductSales
from Sale
Group by product_id
)
select a.ProductID, ISNULL(b.ProductSales,0) as Sales
from products a left join SalesSummary b on a.product_id=b.product_id

MYSQL - Get a COUNT of rows from table 1 based on average of column in table 2

Hopefully somebody can help with this - had me stumped all afternoon.
I have 2 tables:
products - id | name | active
product_reviews - id | product_id | rating
The product_reviews contains multiple rows, each one containing a rating of the parent product.
What I'm trying to do is obtain a COUNT of all the products for each rating, for example:
Rating 1 or above - 50 products
Rating 2 or above - 40 products
Rating 3 or above - 30 products
Rating 4 or above - 20 products
Rating 5 - 10 products
So far I have tried WHERE, SUBQUERY, HAVING and get inconsistent results, the closest I've got so far is:
SELECT products.id FROM `products`
INNER JOIN `product_reviews` ON `product_reviews`.`product_id` = `products`.`id`
WHERE `products`.`active` = '1'
HAVING (AVG(product_reviews.rating) > 1)
...and then counting the results, but these do not seem to be correct, obviously if I use COUNT(products.id) it will say 'incorrect use of aggregate'.
You can try this query to get the number of products which are greater than or equal to one.
SELECT COUNT(DISTINCT product_reviews.product_id)
FROM `product_reviews`
INNER JOIN `products`
ON `product_reviews`.`product_id` = `products`.`id`
WHERE `products`.`active` = '1'
AND `product_reviews`.`rating` >= 1
But you have to run the query 5 times to get products for different review groups

join values of 2 tables and display data

I have 2 tables, cart and product. User can choose product from product table and then its details are added to cart table. i wanted a listing that combines the values of these two tables and gives a result
prodsize
id catid catname productid prodsize cost prodname
1 2 CN1 13 small 130 P1
2 2 CN1 13 large 200 P1
3 2 CN1 14 small 50 P2
4 2 CN1 14 medium 90 P2
5 2 CN1 14 large 110 P2
6 2 CN1 12 small 70 P3
7 2 CN1 12 medium 110 P3
8 2 CN1 13 medium 200 P1
cart
id catid catname userid productid prodname prodsize prodcost quantity status
1 2 CN1 1 13 P1 small 130 2 add_to_cart
1 2 CN1 1 13 P1 large 200 2 order_placed
when i run the following query combined value from both the table but here i want that only those products quantity should get displayed whose status is add_to_cart, if the status is order_placed then the quantity should be 0, can anyone plz tell how can i modify the below code to get desired result
$sql= "SELECT p.catid, p.catname, p.productid, p.prodimg, GROUP_CONCAT(p.prodsize ORDER BY p.id ASC) as size, GROUP_CONCAT(p.cost ORDER BY p.id ASC) as cost, p.prodname,
GROUP_CONCAT(c.prodsize,'-',c.quantity) as cart_details, GROUP_CONCAT(DISTINCT(c.userid)) as user_id
FROM productsize p
LEFT JOIN cart c ON(c.productid = p.productid AND c.userid = '$userid' AND p.prodsize = c.prodsize)
WHERE p.catid ='$catid'
GROUP BY p.productid
ORDER BY user_id DESC, p.productid ASC";
I'm a little confused about your two conditions ("ordered" items shouldn't get displayed, and should have quantity 0). If they have a quantity 0, they need to be displayed, right? Anyhow, here's my fix considering you may want to do the latter (get "ordered" items in your query result with a quantity of 0)
You need to group by productid AND status
You need a quantity as an aggregate SUM that takes the status into account
Cleaned up some other things too (e.g. quoted indexes, which will harm performance):
$sql = "SELECT p.catid, p.catname, p.productid, p.prodimg,
GROUP_CONCAT(p.prodsize ORDER BY p.id ASC) as size,
GROUP_CONCAT(p.cost ORDER BY p.id ASC) as cost, p.prodname,
GROUP_CONCAT(c.prodsize,'-',c.quantity) as cart_details,
GROUP_CONCAT(DISTINCT(c.userid)) as user_id,
SUM(CASE WHEN c.status = 'add_to_cart' THEN quantity ELSE 0 END) AS quantity
FROM productsize p
LEFT JOIN cart c ON(c.productid = p.productid
AND p.prodsize = c.prodsize)
AND c.userid = {$userid}
WHERE p.catid = {$catid}
GROUP BY p.productid, c.status
ORDER BY p.productid ASC";
You've already got the where clause. Try adding
AND status = 'add_to_cart'
just after the existing where clause.
Change c.quantity to:
case c.status
when 'add_to_cart' then c.quantity
else 0
end
Since you used a left join, the zero result will also apply when that product didn't appear in the user's cart.
And note that the sort on userid may be effectively ordering the cart and non-cart products but that is the wrong way to express that intention. It's also best to aggregate the non-group columns everywhere.

How to find Profit for Category

My project is about a jewelery store and i try to find the profit of each product-category.
Let me be more specific
I have 3 tables which gives me the info:
SALES(salesid,productid,quantity,price)
salesid productid Quantity Price
11001 13001 4 5
11002 13002 6 10
11003 13003 5 16
.
.
11012 13012 7 15
RETURN(salesid,productid,date,quantity,price)
salesid productid Quantity Price
11003 13003 1 16
11007 13007 3 12
11008 13008 3 8
PROCUREMENT(procurementid,productid,quantity,price)
procurementid productid Quantity Price
100001 13001 10 2
100002 13002 10 2
.
.
100012 13012 10 2
product_category(categoryid,category)
categoryid category
1 Gold
2 Silver
.
5 Platin
product(Productid,categoryid)
Productid categoryid
13001 1
13002 3
.
.
13010 5
The profit is given from this type:
Profit=Quantity*Price(Sell)-Quantity*Price(Return)-Quantity*Price(Procurement)
And now here is the problem.. I came up to this so far
SELECT categoryid,
category,
(coalesce(a.rev,0)- coalesce(b.ret,0),
coalesce(c.cost,0)) AS profit
FROM product category AS g
JOIN product AS h ON g.categoryid = h.categoryid
JOIN
(SELECT categoryid,
sum(quantity*price) AS rev
FROM sales AS a,
product AS b
WHERE a.productid = b.productid
GROUP BY categoryid) a
LEFT OUTER JOIN
(SELECT cartegoryid,
sum(quantity*price) AS ret
FROM RETURN AS a ,
product AS b
WHERE a.productid = b.productid
GROUP BY categoryid) b ON a.categoryid = b.categoryid
LEFT OUTER JOIN
(SELECT categoryid,
sum(quantity*price) AS cost
FROM procurement AS a,
product AS b
WHERE a.productid = b.productid
GROUP BY categoryid) c ON a.categoryid = c.categoryid ,
product AS d,
procurement AS e
WHERE MONTH(f.date) = MONTH(e.date)
AND YEAR(date) = 2013
[sorry for the align i am new to the site dont know how to copy paste code well(:D)]
wahtever when i do this it comes to a state like
categoryid category profit
1 Gold -100
2 Silver -100
.
5 Platin -100
dont know where is the problem...i made a lot of changes and switches but nothing came up...any suggestion would be so helpfull.Thank u in advane
Initially looks like your profit formula has an extra comma in it.
this
(coalesce(a.rev,0) - coalesce(b.ret,0),coalesce(c.cost,0)) as profit
should be this
coalesce(a.rev,0) - coalesce(b.ret,0) - coalesce(c.cost,0) AS profit
Few more issues with this query
Right before the where clause, after you join the cost subquery, you add product and procurement tables but don't join them. This will cause a cartesian join which will throw off your results.
In the where clause you don't specify which tables date field you want to use. AND YEAR(date) = 2013 should be e.date or f.date. That should have given you an error if you tried to run it.
WHERE MONTH(f.date) = MONTH(e.date) which table is f.date referring to? You didn't give an alias of f to any table.
You join in procurement and use its date field to filter results by month, but none of your revenue, returns, and cost subquery totals take dates into account. This will throw off your results.