I have a table called Product. I need to select all product records that have the MAX ManufatureDate.
Here is a sample of the table data:
Id ProductName ManufactureDate
1 Car 01-01-2015
2 Truck 05-01-2015
3 Computer 05-01-2015
4 Phone 02-01-2015
5 Chair 03-01-2015
This is what the result should be since the max date of all the records is 05-01-2015 and these 2 records have this max date:
Id ProductName ManufactureDate
2 Truck 05-01-2015
3 Computer 05-01-2015
The only way I can think of doing this is by first doing a query on the entire table to find out what the max date is and then store it in a variable #MaxManufatureDate. Then do a second query where ManufactureDate=#MaxManufactureDate. Something tells me there is a better way.
There are 1 million+ records in this table:
Here is the way I am currently doing it:
#MaxManufactureDate = select max(ManufactureDate) from Product
select * from Product where ManufactureDate = #MaxManufactureDate
If figure this is a lot better then doing a subselect in a where clause. Or is this the same exact thing as doing a subselect in a where clause? I am not sure if the query gets ran for each row regardless or if sqlserver stored the variable value in memory.
select * from product
where manufactureDate = (select max(manufactureDate) from product)
The inner select-statements selects the maximum date, the outer all products which have the date.
You can use a subQuery
SELECT *
FROM Product
WHERE ManufactureDate = (
SELECT ManufactureDate
FROM Product
ORDER BY ManufactureDate
LIMIT 1
);`
You may need to use ASC or DESC to collect the right order
Try this pattern:
SELECT Id, ProductName, ManufactureDate
FROM (
SELECT Id, ProductName, ManufactureDate, MAX(ManufactureDate)OVER() AS MaxManufactureDate
FROM Product P
) P
WHERE P.MaxManufactureDate = P.ManufactureDate
Essentially, use a window function to get the data you're looking for in the inline view, then use the where clause in the outer query to match them.
Related
Hi All i am unable to create a query in sql i want to get all employee who's contain the product which i passed in parameter
Ex, i if passed product id 11,12 then its should be return only DeliveryBoyId1 and 2 and if passed the product id 11 then its should be return only DeliveryBoyId 1,2,3 and if i passed productid 11,12,16 then its should return 0 record because there is no delivery boy assigned the product id 11,12,16
I don't know what your table is called so I'm calling it dbo.Delivery. Try this out:
;with CTE as (
select distinct DeliveryBoyId --get all the boys who delivered product 11
from dbo.Delivery
where ProductId = 11
union all --combine the above results with the below
select distinct DeliveryBoyId --get all the boys who delivered product 12
from dbo.Delivery
where ProductId = 12
)
select DeliveryBoyId
from CTE
group by DeliveryBoyId
having count(1) = 2 --get all the boys who appear twice in the above table, once for each product
If you want to match additional products, you can add to the CTE section for other product IDs.
If you want a single solution for any number of products, you can use this instead (which may be a little less readable but more concise and easier to maintain):
select DeliveryBoyId
from (
select distinct DeliveryBoyId, ProductId
from dbo.Delivery
where ProductId in (11, 12)
) s
group by DeliveryBoyId
having count(1) = 2 --number matches number of products you need to match
My table is like this:
ProductID ProductName SupplierID CategoryID Unit Price
1 Chais 1 1 10 boxes x 20 bags 18
2 Chang 1 1 24 - 12 oz bottles 19
3 Aniseed Syrup 1 2 12 - 550 ml bottles 10
4 Chef Anton's
Cajun Seasoning 2 2 48 - 6 oz jars 21.35
5 Chef Anton's
Gumbo Mix 2 2 36 boxes 25
I copy it from https://www.w3schools.com/sql/sql_func_max.asp
I tried the simple version of MAX() function test, it works. But when I use the HighestPrice in the WHERE condtion as following:
SELECT
MAX(Price) AS HighestPrice,
SupplierID
FROM Products
GROUP BY SupplierID
WHERE HighestPrice>20;
The sytem report ERROR as:
Error: misuse of aggregate: MAX()
Does it mean I must use inner join to get what I want?
Following query should work:
SELECT SupplierID, MAX(Price) AS HighestPrice
FROM Products
GROUP BY SupplierID
HAVING MAX(Price) > 20;
following is the correct syntax of writing any SQL query:
SELECT column_name1,
SUM(column_name2)
FROM table_name
WHERE [CONDITION]
GROUP BY column_name1
HAVING (arithematic function condition);
Use having instead of where .
Where is always used before group by statement. It is way to filter the data which is already available with us whereas having is used after group by statement because it is applied on the data which we are in process of making.
SELECT MAX(Price) AS HighestPrice, SupplierID
FROM Products
Group By SupplierID
having MAX(Price) > 20;
Let me know in case of any queries.
Just for fun. If you specifically want to use where condition for highest price instead of having clause as given by G.arima with max function again. Do this:-
SELECT *
FROM
(
SELECT
MAX(Price) AS HighestPrice,
SupplierID
FROM Products
GROUP BY SupplierID
) a
WHERE HighestPrice>20;
Hope it helps :-)
By way of explanation of G.arima’s answer above:
When you use GROUP BY, you effectively create a new virtual table which contains only the GROUP BY fields as well as summaries.
There are two filter clauses, WHERE and HAVING, but they have a distinct role.
WHERE filters the original table. This gives you the formula FROM … WHERE …
HAVING filters the groups. This gives you the formula GROUP BY … HAVING …
What you ask is OK, but the clause is the wrong one. As G.arima says, you should use HAVING.
I have the following table which contains ID's and UserId's.
ID UserID
1111 11
1111 300
1111 51
1122 11
1122 22
1122 3333
1122 45
I'm trying to count the distinct number of 'IDs' so that I get a total, but I also need to get a total of ID's that have also seen the that particular ID as well... To get the ID's, I've had to perform a subquery within another table to get ID's, I then pass this into the main query... Now I just want the results to be displayed as follows.
So I get a Total No for ID and a Total Number for Users ID - Also would like to add another column to get average as well for each ID
TotalID Total_UserID Average
2 7 3.5
If Possible I would also like to get an average as well, but not sure how to calculate that. So I would need to count all the 'UserID's for an ID add them altogether and then find the AVG. (Any Advice on that caluclation would be appreciated.)
Current Query.
SELECT DISTINCT(a.ID)
,COUNT(b.UserID)
FROM a
INNER JOIN b ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999)
GROUP BY a.ID
Which then Lists all the IDs and COUNT's all the USERID.. I would like a total of both columns. I've tried warpping the query in a
SELECT COUNT(*) FROM (
but this only counts the ID's which is great, but how do I count the USERID column as well
You seem to want this:
SELECT COUNT(DISTINCT a.ID), COUNT(b.UserID),
COUNT(b.UserID) * 1.0 / COUNT(DISTINCT a.ID)
FROM a INNER JOIN
b
ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999);
Note: DISTINCT is not a function. It applies to the whole row, so it is misleading to put an expression in parentheses after it.
Also, the GROUP BY is unnecessary.
The 1.0 is because SQL Server does integer arithmetic and this is a simple way to convert a number to a decimal form.
You can use
SELECT COUNT(DISTINCT a.ID) ...
to count all distinct values
Read details here
I believe you want this:
select TotalID,
Total_UserID,
sum(Total_UserID+TotalID) as Total,
Total_UserID/TotalID as Average
from (
SELECT (DISTINCT a.ID) as TotalID
,COUNT(b.UserID) as Total_UserID
FROM a
INNER JOIN b ON someID = someID
WHERE a.ID IN ( SELECT ID FROM c WHERE GROUPID = 9999)
) x
I have large database and one field should be an incremental number, but it sometimes resets and I must detect them (the bold rows)
Table 1:
Shop #Sell DATE
EC1 56 1/10/2015
EC1 57 2/10/2015
**EC1 11 3/10/2015
EC1 12 4/10/2015**
AS2 20 1/10/2015
AS2 21 2/10/2015
AS2 22 3/10/2015
AS2 23 4/10/2015
To solve this problem I thought to find the highest number of each SHOP and check if it is the number with the highest DATE. Do you know another easier way to do it?
My concern is that it can be a problem to do the way I am thinking since I have a large database.
Do you know how I can do the query I am thinking of or do you have any others ideas?
The query you have in mind will give you all Shop values having a discontinuity in Sell number.
If you want to get the offending record you can use the following query:
SELECT Shop, Sell, DATE
FROM (
SELECT Shop, Sell, DATE,
LAG(Sell) OVER (PARTITION BY Shop ORDER BY DATE) AS prevSell
FROM Shops ) t
WHERE Sell < prevSell
ORDER BY DATE
LIMIT 1
The above query will return the first discontinuity found within each Shop partition.
Output:
Shop Sell DATE
---------------------
EC1 11 2015-03-10
Demo here
EDIT:
In case you cannot use windowed function and you only want the id of the shop having the discontinuity, then you can use the following query:
SELECT s.Shop
FROM Shops AS s
INNER JOIN (
SELECT Shop, MAX(Sell) AS Sell, MAX(DATE) AS DATE
FROM Shops
GROUP BY Shop ) t
ON s.Shop = t.Shop AND s.DATE = t.DATE
WHERE t.Sell <> s.Sell
The above will work provided that you have unique DATE values per Shop.
I think the following is the type of query you want:
select s.*
from (select shop, max(sell) as maxsell,
first_value(sell) over (partition by shop order by date desc) as lastsell
from shops s
group by shop
) s
where maxsell <> lastsell;
I have a little problem.
My table is:
Bill Product ID Units Sold
----|-----------|------------
1 | 10 | 25
1 | 20 | 30
2 | 30 | 11
3 | 40 | 40
3 | 20 | 20
I want to SELECT the product which has sold the most units; in this sample case, it should be the product with ID 20, showing 50 units.
I have tried this:
SELECT
SUM(pv."Units sold")
FROM
"Products" pv
GROUP BY
pv.Product ID;
But this shows all the products, how can I select only the product with the most units sold?
Leaving aside for the moment the possibility of having multiple products with the same number of units sold, you can always sort your results by the sum, highest first, and take the first row:
SELECT pv."Product ID", SUM(pv."Units sold")
FROM "Products" pv
GROUP BY pv."Product ID"
ORDER BY SUM(pv."Units sold") DESC
LIMIT 1
I'm not quite sure whether the double-quote syntax for column and table names will work - exact syntax will depend on your specific RDBMS.
Now, if you do want to get multiple rows when more than one product has the same sum, then the SQL will become a bit more complicated:
SELECT pv.`Product ID`, SUM(pv.`Units sold`)
FROM `Products` pv
GROUP BY pv.`Product ID`
HAVING SUM(pv.`Units sold`) = (
select max(sums)
from (
SELECT SUM(pv2.`Units sold`) as "sums"
FROM `Products` pv2
GROUP BY pv2.`Product ID`
) as subq
)
Here's the sqlfiddle
SELECT SUM(pv."Units sold") as `sum`
FROM "Products" pv
group by pv.Product ID
ORDER BY sum DESC
LIMIT 1
limit 1 + order by
The Best and effective way to this is Max function
Here's The General Syntax of Max function
SELECT MAX(ID) AS id
FROM Products;
and in your Case
SELECT MAX(Units Sold) from products
Here is the Complete Reference to MIN and MAX functions in Query
Click Here