I have a products table that contains date-of-create, price, rate,....... and multiple columns I need one select statement that returns the 10 newest records, 10 lowest prices and the top rated products as separated result of each other something like
(select top 10 from products Order By Date ASC ) as newest_list
(select top 10 from products Order By price DESC ) as price_list
(select top 10 from products Order By Rate ASC ) as rateList_list
where ( newest_list price_list rateList_list) are different table result
Which better way to approach that result. Thanks.
You basically want union all . . . and a subquery:
select *
from ((select top 10 'newest' as which, p.*
from products p
Order By Date ASC
) union all
(select top 10 'priciest', p.*
from products p
Order By price DESC
) union all
(select top 10 'ratiest', p.*
from products p
Order By Rate ASC
)
) p
If you don't want duplicates, you can use union or window functions:
select p.*
from (select p.*,
row_number() over (order by date desc) as seqnum_d,
row_number() over (order by price desc) as seqnum_p,
row_number() over (order by rate asc) as seqnum_r
from p
) p
where seqnum_d <= 10 or seqnum_p <= 10 or seqnum_r <= 10;
Related
I'm trying to make a query that outputs a list with the company data and the number of Products and Discounts of each Company and order by product_count.
Also i need to limit the output to groups of 30 rows
SELECT * FROM (
SELECT *, (
SELECT COUNT(*) FROM Products WHERE Product_Comp_id = Comp_id
) as product_count, (
SELECT COUNT(*) FROM Discount WHERE Disc_Comp_id = Comp_id
) as discount_count , ROW_NUMBER() OVER (
ORDER BY product_count ASC
) AS RowNum FROM Company
) AS finalTable WHERE finalTable.RowNum BETWEEN 0 AND 30
But i get this error
Invalid column name 'product_count'.
Table Structure
Products
|-Product_id
|-Product_Name
|-Product_Description
|-Product_Comp_id
Discount
|-Disc_id
|-Disc_Name
|-Disc_Comp_id
|-Disc_Ammount
Company
|-Comp_id
|-Comp_Name
|-Comp_Address
You need an additional level of subquery to give you product_count.
SELECT * FROM (
SELECT * , ROW_NUMBER() OVER (ORDER BY product_count ASC) AS RowNum
FROM
(
SELECT *, (SELECT COUNT(*) FROM Products WHERE Product_Comp_id = Comp_id) as product_count,
(SELECT COUNT(*) FROM Discount WHERE Disc_Comp_id = Comp_id) as discount_count
FROM Company
) C
) AS finalTable WHERE finalTable.RowNum BETWEEN 0 AND 30
Suppose we have such an sql query, with joined data from another table.
SELECT
pr.num, pr.resort_id, p.src_mask
FROM
rutraveler.rt_photo_resort AS pr
JOIN rutraveler.rt_photo AS p ON pr.photo_id = p.id
WHERE pr.resort_id = '612' AND p.src_mask is not null
ORDER BY num
LIMIT 30
So far we have to do several queries for several resort_id.
How to change the query so that we have only one query (WHERE resort_id in (612, 333, 111) with result no more than 30 items per each resort_id?
Use ROW_NUMBER to count the rows per resort_id.
SELECT resort_id, num, resort_id, src_mask
FROM
(
SELECT
pr.resort_id, pr.num, pr.resort_id, p.src_mask,
ROW_NUMBER() OVER (PARTITION BY pr.resort_id ORDER BY num) AS rn
FROM
rutraveler.rt_photo_resort AS pr
JOIN rutraveler.rt_photo AS p ON pr.photo_id = p.id
WHERE resort_id in (612, 333, 111) AND p.src_mask is not null
) data
WHERE rn <= 30
ORDER BY resort_id, num;
you can use CTE with ROW_NUMBER() and PARTITION BY
WITH Results_CTE AS
(
SELECT
pr.num, pr.resort_id, p.src_mask,ROW_NUMBER() over ( PARTITION BY pr.resort_id ORDER BY num) As Row_number
FROM
rutraveler.rt_photo_resort AS pr
JOIN rutraveler.rt_photo AS p ON pr.photo_id = p.id
WHERE pr.resort_id IN (A,B,C) AND p.src_mask is not null
)
SELECT *
FROM Results_CTE
WHERE Row_number <= 30
I have a Products table on SQL Server. How can I select a random row from the top 10 rows - ranked by sales_count?
After finding an answer for how to select random rows, this is what I have so far:
SELECT * FROM (
SELECT TOP 1 * FROM
(
SELECT TOP 10 *
From Products
ORDER BY "sales_count" DESC
) a
ORDER BY NEWID()) b
)
But I'm not sure it's correct?
There is one additional layer of subquery in your version. So assuming the columns and tables are correct, this should work:
SELECT TOP 1 p.*
FROM (SELECT TOP 10 p.*
FROM Products p
ORDER BY "sales_count" DESC
) p
ORDER BY NEWID();
If you wanted to be fair, you might add WITH TIES:
SELECT TOP (1) p.*
FROM (SELECT TOP (10) WITH TIES p.*
FROM Products p
ORDER BY "sales_count" DESC
) p
ORDER BY NEWID();
I'm trying to get the most expensive and cheapest items from two different tables.
The output should be one row with the values for MostExpensiveItem, MostExpensivePrice, CheapestItem, CheapestPrice
I was able to get the price of the most expensive and cheapest items in the two tables with following query:
SELECT
MAX(ExtrasPrice) as MostExpensivePrice, MIN(ExtrasPrice) as CheapestPrice
FROM
(
SELECT ExtrasPrice FROM Extras
UNION ALL
SELECT ItemPrice FROM Items
) foo
How can I add the names of the items (ItemName, ExtrasName) to my output? Again, there should only be one row as the output.
Try this:
SELECT TOP 1 FIRST_VALUE(Price) OVER (ORDER BY Price) AS MinPrice,
FIRST_VALUE(Name) OVER (ORDER BY Price) AS MinName,
LAST_VALUE(Price) OVER (ORDER BY Price DESC) AS MaxPrice,
LAST_VALUE(Name) OVER (ORDER BY Price DESC) AS MaxName
FROM (
SELECT ExtrasName AS Name, ExtrasPrice AS Price FROM Extras
UNION ALL
SELECT ItemName As Name, ItemPrice AS Price FROM Items) u
SQL Fiddle Demo
TOP 1 with order by clause should work for you. Try this
SELECT *
FROM (SELECT TOP 1 ExtrasPrice,ExtrasName
FROM Extras ORDER BY ExtrasPrice Asc),
(SELECT TOP 1 ItemPrice,ItemName
FROM Items ORDER BY ItemPrice Desc)
Note: Comma can be replaced with CROSS JOIN
You can use row_number() for this. If you are satisfied with two rows:
SELECT item, price
FROM (SELECT foo.*, row_number() over (order by price) as seqnum_asc,
row_number() over (order by price) as seqnum_desc
FROM (SELECT item, ExtrasPrice as price FROM Extras
UNION ALL
SELECT item, ItemPrice FROM Items
) foo
) t
WHERE seqnum_asc = 1 or seqnum_desc = 1;
EDIT:
If you have an index on "price" in both tables, then the cheapest method is probably:
with exp as (
(select top 1 item, ExtrasPrice as price
from Extras e
order by price desc
) union all
(select top 1 i.item, ItemPrice
from Items i
order by price desc
)
),
cheap as (
(select top 1 item, ExtrasPrice as price
from Extras e
order by price asc
) union all
(select top 1 i.item, ItemPrice
from Items i
order by price asc
)
)
select top 1 *
from exp
order by price desc
union all
select top 1 *
from cheap
order by price asc;
If you want this in one row, you can replace the final query with:
select e.*, c.*
from (select top 1 *
from exp
order by price desc
) e cross join
(select top 1 *
from cheap
order by price asc
) c
In SQL Server, suppose we have a SALES_HISTORY table as below.
CustomerNo PurchaseDate ProductId
1 20120411 12
1 20120330 13
2 20120312 14
3 20120222 16
3 20120109 16
... and many records for each purchase of each customer...
How can I write the appropriate query for finding:
For each customer,
find the product he bought at MOST,
find the percentage of this product over all products he bought.
The result table must have columns like:
CustomerNo,
MostPurchasedProductId,
MostPurchasedProductPercentage
Assuming SQL Server 2005+, you can do the following:
;WITH CTE AS
(
SELECT *,
COUNT(*) OVER(PARTITION BY CustomerNo, ProductId) TotalProduct,
COUNT(*) OVER(PARTITION BY CustomerNo) Total
FROM YourTable
), CTE2 AS
(
SELECT *,
RN = ROW_NUMBER() OVER(PARTITION BY CustomerNo
ORDER BY TotalProduct DESC)
FROM CTE
)
SELECT CustomerNo,
ProductId MostPurchasedProductId,
CAST(TotalProduct AS NUMERIC(16,2))/Total*100 MostPurchasedProductPercent
FROM CTE2
WHERE RN = 1
You still need to deal when you have more than one product as the most purchased one. Here is a sqlfiddle with a demo for you to try.
Could do a lot prettier, but it works:
with cte as(
select CustomerNo, ProductId, count(1) as c
from SALES_HISTORY
group by CustomerNo, ProductId)
select CustomerNo, ProductId as MostPurchasedProductId, (t.c * 1.0)/(select sum(c) from cte t2 where t.CustomerNo = t2.CustomerNo) as MostPurchasedProductPercentage
from cte t
where c = (select max(c) from cte t2 where t.CustomerNo = t2.CustomerNo)
SQL Fiddle