I have two tables (sql server), as shown below:
locations
id cubicfeet order
-------------------------------------
1 5 1
2 10 1
3 6 1
items
id cubic feet order
--------------------------------------
1 6 1
2 6 1
3 6 1
I need a query to tell me if all the items will fit into all the locations (for a given order). If all items will not fit into 1 or all locations then I need to create a new location for that given order - and then move any items that DID fit into the locations before to the new location (as many as fit). The new location will only be given a certain amount of cubic feet also - say 17. In this example, sum won't work because all 3 records are 6 so the sum is 18, which is less than the sum of 5,10,6, but the location with volume 5 can't fit any of the items since they are all volume 6 cubic feet.
the only way I think I can do it is creating temp tables in my sp and using a while loop to go through them and update the locations 1 at a time to see if it still fits more...
Related
I have a table that looks like:
col1
------
2
2
3
4
5
6
7
with values sorted in ascending order.
I want to assign each row to groups with labels 0,1,...,n so that each group has a total of no more than 10. So in the above example it would look like this:
col1 |label
------------
2 0
2 0
3 0
4 1
5 1
6 2
7 3
I tried using this:
floor(sum(col1) OVER (partition by ORDER BY col1 ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) /10))
But this doesn't work correctly because it is performing the operations
as:
floor(2/10) = 0
floor([2+2]/10) = 0
floor([2+2+3]/10) = 0
floor([2+2+3+4]/10) = 1
floor([2+2+3+4+5]/10 = 1
floor([2+2+3+4+5+6]/10 = 2
floor([2+2+3+4+5+6+7]/10) = 2
It's all coincidentally correct until the last calculation, because even though
[2+2+3+4+5+6+7] / 10 = 2.9
and
floor(2.9) = 2
what it should do is realise 6+7 is > 10 so the 5th row with value 7 needs be in its own group so iterate the group number + 1 and allocate this row into a new group.
What I really want it to do is when it encounters a sum > 10 then set group number = group number + 1, allocate the CURRENT ROW into this new group, and then finally set the new start row to be the CURRENT ROW.
This is too long for a comment.
Solving this problem requires scanning the table, row-by-row. In SQL, this would be through a recursive CTE (or hierarchical query). Hive supports neither of these.
The issue is that each time a group is defined, the difference between 10 and the sum is "forgotten". That is, when you are further down in the list, what happens earlier on is not a simple accumulation of the available data. You need to know how it was split into groups.
A related problem is solvable. The related problem would assign all rows to groups of size 10, splitting rows between two groups. Then you would know what group a later row is in based only on the cumulative sum of the previous rows.
I'm new to mdx and need your help:
[Item].[Segment] [Country].[World] [Measures].[Periodic]
1 Region A 150
2 Region B 60
3 Region C 1400
4 Region D 20
I have two dimensions Segment and World. If I take only world, I get no values. But I want to achieve to combine the two dimensions to one dimension on segment level as following:
[Item].[Segment] [Measures].[Periodic]
1 150
2 60
3 1400
4 20
Would an aggregation be useful in this case?
Thanks in advance!
The Structure is like following:
Cube_Structure
--> I need to combine both dimensions Segment and World in order to have one dimension on the row which shows me the values for the segments only!
So I have a column with this data
1
1
1
2
3
4
5
5
5
how can I do a count if where the value at any given location in the above table is equal to a cell i select? i.e. doing Count([NUMBER]) Where([NUMBER] = Coordinates(0,0)) would return 3, because there are 3 rows where the value is one in the 0 position.
it's basically like in excel where you can do COUNTIF(A:A, 1) and it would give you the total number of rows where the value in A:A is 1. is this possible to do in business objects web intelligence?
Functions in WebI operate on rows, so you have to think about it a little differently.
If your intent is to create a cell outside of the report block and display the count of specific values, you can use Count() with Where():
=Count([NUMBER];All) Where ([NUMBER] = "1")
In a freestanding cell, the above will produce a value of "3" for your sample data.
If you want to put the result in the same block and have it count up the occurrences of values on that row, for example:
NUMBER NUMBER Total
1 3
1 3
1 3
2 1
3 1
4 1
5 3
5 3
5 3
it gets a little more complicated. You have to have at least one other dimension in the query to reference. It can be anything, but you have to be counting something in conjunction with the NUMBER dimension. So, the following would work, assuming there's another dimension in the query named [Duh]:
=Count([NUMBER];All) ForAll([Duh])
Full disclosure, this is for an assignment I don't think I'm looking for spoon feeding, more so just a general question. Am a I allowed to break that into a group of 8 and 2 groups of 4, or do all group sizes have to be equal, ie 4 groups of 4
1 0 1 1
0 0 0 0
1 1 1 1
1 1 1 1
Sorry if this is obvious, but my searches haven't been explicit and my teacher was quite vague. Thanks!
TL;DR: Groups don't have to be equal in size.
Let see what happens if, in your case, you take 11 groups of one. Then you will have an equation of eleven terms. (ie. case_1 or case_2 or... case_11).
By making big group, in your case 1 group of 8 and 2 groups of 4, you will have a very short and simplified equation like: case_group_8 or case_group_4_1 or case_group_4_2.
Both grouping are correct (we took all the one in the map) but the second is the most optimized. (i.e. you cannot simplified more)
Making 4 groups of 4 will bring you an equation that can be simplified more.
The best way now is for you to try both grouping (all 4 vs 8/4/4) and see the output result.
I have to retrieve only particular records whose sum value of size field is <=150.
I have table like below ...
userid size
1 70
2 100
3 50
4 25
5 120
6 90
The output should be ...
userid size
1 70
3 50
4 25
For example, if we add 70,50,25 we get 145 which is <=150.
How would I write a query to accomplish this?
Here's a query which will produce the above results:
SELECT * FROM `users` u
WHERE (select sum(size) from `users` where size <= u.size order by size) < 150
ORDER BY userid
However, the problem you describe of wanting the selection of users which would most closely fit into a given size, is a bin packing problem. This is an NP-Hard problem, and won't be easily solved with ANSI SQL. However, the above seems to return the right result, but in fact it simply starts with the smallest item, and continues to add items until the bin is full.
A general, more effective bin packing algorithm would is to start with the largest item and continue to add smaller ones as they fit. This algorithm would select users 5 and 4.
What you're looking for is a greedy algorithm. You can't really do this with one SQL statement.
It's similar to the subset sum problem. You are definitely going to be into exponential time ...
There are several ways to solve subset
sum in time exponential in N. The most
naïve algorithm would be to cycle
through all subsets of N numbers and,
for every one of them, check if the
subset sums to the right number. The
running time is of order O(2^N*N), since
there are 2N subsets and, to check
each subset, we need to sum at most N
elements.
Unless you can constrain the problem to smaller subsets.
According to your definition as it stands you could get any of these tables:
userid size userid size
1 70 2 100
userid size userid size
3 50 4 25
userid size userid size
5 120 6 90
userid size userid size
1 70 2 100
3 50 3 50
userid size userid size
1 70 2 100
4 25 4 25
userid size userid size
1 70 4 25
3 50 6 90
4 25
userid size userid size
4 25 3 50
5 120 6 90
SQL sucks at guessing. Do you mean to say you want the most users who's total size is under a certain limit? You'll need to create a temp table of all the combinations of users, then select the ones who's total size is less then the limit, then select the one with the most users, and possibly the lowest user ID or something. Either way, it won't be fast due to the first step.
But do you want to maximize the number of results or minimize or you simply don't care? first two cases is constraints optimization for which there should be solution using SQL, the latter (as mentioned above) requires greedy strategy.