I want to order the following things by their Ordernum (unique) regarding the RefID (which holds the same products together) with SQL on a Oracle Database:
It has to be first ordered by OrderNum followed by every product with the same RefID. The row with the lowest OrderNum should be first, then the products with the same RefID, after that the next higher OrderNum and so on...
OrderNum | RefID | ID
10 | 100 | 8
1 | 200 | 9
2 | 100 | 4
8 | 200 | 12
3 | 200 | 20
0 | 10 | 11
What I tried and what gives me just the result ordered by OrderNum, not regarding the same RefIDs:
SELECT * FROM products
ORDER BY OrderNum, RefID
Expected result
0 | 10 | 11
1 | 200 | 9
3 | 200 | 20
8 | 200 | 12
2 | 100 | 4
10 | 100 | 8
I think this has to be done with a subselect, right? But how does this look like?
I believe that Oracle supports CTE and window functions, so something like the following should work:
WITH Extras as (
SELECT
p.*,
MIN(OrderNum) OVER (PARTITION BY RefID) as LowNum,
ROW_NUMBER() OVER (PARTITION BY RefID ORDER BY OrderNum) as rn
FROM
Products p
)
SELECT * from Extras ORDER BY LowNum,rn;
Common Table Expressions (CTEs) are similar to subqueries but I tend to prefer to use them, all other things being equal - there's no specific advantage in this query, but they can be reused multiple times, and they can easily build on previous ones without introducing lots of nesting.
You are ordering by OrderNum and inside each OrderNum by RefID, but what you want to do is just the opposite, i.e. to order by RefID first and inside each RefID by OrderNum:
SELECT * FROM products
ORDER BY RefID, OrderNum;
Use RefID and OrderNum to order by your result. Use ASC and DESC for proper ordering (default is ASC):
select * from products
order by RefID DESC,OrderNum ASC
Result:
OrderNum RefID ID
-----------------------
1 200 9
3 200 20
8 200 12
2 100 4
10 100 8
Sample result in SQL Fiddle
you want to Ordernum regarding the RefID ,i think it may gives result according you:-
select * from products
order by RefID,OrderNum
Related
I have the following table as an output from a sql statement
user | product | price
…
123 | 12 | 451.29
373 | 12 | 637.28
623 | 12 | 650.84
672 | 16 | 356.87
123 | 16 | 263.90
…
Now I want to get only the row with the smallest price for each product_id
THE SQL is fairly easy
SELECT user, product, price
FROM t
WHERE product IN (
SELECT product_id
FROM p
WHERE typ LIKE 'producttyp1'
)
)
but adding MIN(price) does not work how it usually do. I think its because there are several groups of the same product_ids in the same table. Is there an easy to use solution or do I have to rewrite the whole query?
Edit: when I delete user from the query I can get the product and the smallest price:
12 | 451.29
16 | 263.90
But now I would have to join the user, which I am trying to avoid.
You can use row_number():
select p.*
from (select p.*,
row_number() over (partition by product order by price asc) as seqnum
from p
) p
where seqnum = 1;
I have an issue similar to the following query:
select name, number, id
from tableName
order by id
limit 10 offset 5
But in this case I only take the 10 elements from the group with offset 5
Is there a way to set limit and offset by id?
For example if I have a set:
|------------------------------------|---|---------------------------------------|
| Ana | 1 | 589d0011-ef54-4708-a64a-f85228149651 |
| Jana | 2 | 589d0011-ef54-4708-a64a-f85228149651 |
| Jan | 3 | 589d0011-ef54-4708-a64a-f85228149651 |
| Joe | 2 | 64ed0011-ef54-4708-a64a-f85228149651 |
and if I have skip 1 I should get
|------------------------------------|---|---------------------------------------|
| Jana | 2 | 589d0011-ef54-4708-a64a-f85228149651 |
| Jan | 3 | 589d0011-ef54-4708-a64a-f85228149651 |
I think that you want to filter by row_number():
select name, number, id
from (
select t.*, row_number() over(partition by name order by id) rn
from mytable t
) t
where
rn >= :number_of_records_per_group_to_skip
and rn < :number_of_records_per_group_to_skip + :number_of_records_per_group_to_keep
The query ranks records by id withing groups of records having the same name, and then filters using two parameters:
:number_of_records_per_group_to_skip: how many records per group should be skipped
:number_of_records_per_group_to_skip: how many records per group should be kept (after skipping :number_of_records_per_group_to_skip records)
This might not be the answer you are looking for but it gives you the results your example shows:
select name, number, id
from (
select * from tableName
order by id
limit 3 offset 0
) d
where id > 1;
Best regards,
Bjarni
I have a table structure with columns similar to the following:
ID | line | value
1 | 1 | 10
1 | 2 | 5
2 | 1 | 6
3 | 1 | 7
3 | 2 | 4
ideally, i'd like to pull the following:
ID | value
1 | 5
2 | 6
3 | 4
one solution would be to do something like the following:
select a.ID, a.value
from
myTable a
inner join (select id, max(line) as line from myTable group by id) b
on a.id = b.id and a.line = b.line
Given the size of the table and that this is just a part of a larger pull, I'd like to see if there's a more elegant / simpler way of pulling this directly.
This is a task for OLAP-functions:
select *
from myTable a
qualify
rank() -- assign a rank for each id
over (partition by id
order by line desc) = 1
Might return multiple rows per id if they share the same max line. If you want to return only one of them, add another column to the order by to make it unique or switch to row_number to get an indeterminate row.
Suppose I have the following table:
--------------------------------------------
ReceiptNo | Date | EmployeeID | Qty
--------------------------------------------
1 | 12-DEC-2015 | 1 | 200
2 | 13-DEC-2015 | 1 | 500
3 | 13-DEC-2015 | 1 | 100
4 | 13-DEC-2015 | 3 | 100
5 | 13-DEC-2015 | 3 | 500
6 | 13-DEC-2015 | 2 | 75
--------------------------------------------
Show the tuples with maximum Qty.
Answer:
--------------------------------------------
2 | 13-DEC-2015 | 1 | 500
5 | 13-DEC-2015 | 3 | 500
--------------------------------------------
I need to use aggregate function MAX().
Is it possible to do so without using nested SELECTS?
Try this in sql server
SELECT TOP 1 WITH TIES *
FROM TABLE
ORDER BY QTY DESC
No.
You can't show the tuples with maximum Qty, using the max aggregate function while avoiding nested selects.
VR46 posted a nice way to do it without using nested selects, but also without the max aggregate. A similar approach can be used in Oracle 12c using the FETCH clause:
select *
from table
order by qty desc
fetch first row with ties
If you want to use the max aggregate, this is the way to do it:
select *
from table
where qty = (select max(qty) from table)
Another way to do it would be using the rank or dense_rank window functions, but they require a nested select, and do not use the max aggregate function:
select *
from (select t.*,
dense_rank() over (order by t.qty desc) as rnk
from table t) t
where t.rnk = 1
Not using max, but plain "cross-platform" ANSI SQL without nested queries:
SELECT t1.*
FROM mytable t1
LEFT OUTER JOIN mytable t2 ON t2.Qty > t1.Qty
WHERE t2.Qty IS NULL
Retrieves all records for which there is no record with a greater quantity in the same table.
The Background
I have a temporary table containing information including a unique rowID, OrderNumber, and guestCount. RowID and OrderNumber already exist in this table, and I am running a new query to fill in the missing guestCount for each orderNumber. I would like to then update the temp table with this information.
Example
What I currently have looks something like this, with only RowID being unique, meaning that there can be multiple items having the same OrderNumber.
RowID | OrderNumber | guestCount
1 | 30001 | 0
2 | 30002 | 0
3 | 30002 | 0
4 | 30003 | 0
My query returns the following table, only returning one total number of guests per orderNumber:
OrderNumber | guestCount
30001 | 3
30002 | 10
30003 | 5
The final table should look like:
RowID | OrderNumber | guestCount
1 | 30001 | 3
2 | 30002 | 10
3 | 30002 | 0
4 | 30003 | 5
I'm only interested in updating one (doesn't matter which) entry per orderNumber, but my current logic is resulting in errors:
UPDATE temp
SET temp.guestCount = cc.guestCount
FROM( SELECT OrderNumber, guestCount
FROM (SELECT OrderNumber, guestCount, RowID = MIN(RowID)
FROM #tempTable
GROUP BY RowID, OrderNumber, guestCount) t)temp
INNER JOIN queryTable q ON temp.OrderNumber = q.OrderNumber
I'm not sure if this logic is even a valid way of doing this, but I do know that I'm getting errors in my update due to the fact that I'm using an aggregate function, as well as a GROUP function. Is there any way to go about this operation differently?
You can define the row to update by using row_number() in a CTE. This identifies the first row in the group for the update:
with toupdate as (
select tt.*, row_number() over (partition by OrderNumber order by id) as seqnum
from #tempTable tt
)
UPDATE toupdate
SET toupdate.guestCount = q.guestCount
FROM toupdate
INNER JOIN queryTable q
ON temp.OrderNumber = q.OrderNumber
where toupdate.seqnum = 1;
The problem with you query is that temp is based on an aggregation subquery. Such a subquery is not updatable, because it does not have a 1-1 relationship with the rows of the original query. Using the CTE with row_number() is updatable. In addition, your set statement uses the table alias cc which is not defined in the query.