I have a table called correctObjects. In this tablet here a lot of grups which has different number records. One example is given below as grup 544 has 5 rows in table. So firstly, I should group all records by GRUP COLUMN then I must do inner matching by CAP COLUMN. So in grup#544 there is three different CAP values then I must give Inner Group number to these records. How can I do these two level grouping process. GRUP column is already done. Inner Grup Column is null in every records.
After Inner Group process, It must look like as belows:
I am using Oracle 11g R2 and PL/SQL Developer
Your question lacks certain details, so I'll just give you a starting point, and you can tweak it to suit your needs.
It's not entirely clear, but the way I understand it, you want to rank the different rows by cap. And I think the ranking is independent for every distinct grup value.
What's not clear to me is why 125 mm is ranked 1, and 62 mm is ranked 2. Is it based on the value? Is it based on which row is the first one, and if so, how are the rows ordered? Or maybe you don't really care which one is first or second, as long as they are grouped correctly. I'll have to assume the latter.
In any case, it sounds like you want to use the dense_rank() analytic function in some form:
select mip, startmi, cap, grup,
dense_rank() over (partition by grup order by cap) as inner_grup
from tbl
Related
How can I retrieve rows where BID comes up multiple times in AID
You can see the sample below, AID and BID columns are under the PrimaryID, and BIDs are under AID. I want to come up with an output that only takes records where BIDs had 1 to many relationship with records on AIDs column. Example output below.
I provided a small sample of data, I am trying to retrieve 20+ columns and joining 4 tables. I have unqiue PrimaryIDs and under those I have multiple unique AIDs, however under these AIDs I can have multiple non-unqiue BIDs that can repeatedly come up under different AIDs.
Hive supports window functions. A window function can associate every row in a group with an attribute of the group. Count() being one of the supported functions. In your case you can use that a and select rows for which that count > 1
The partition by clause you specify which columns define the group, tge same way that you would in the more familiar group by clause.
Something like this:
select * from
(
Select *,
count(*) over (partition by primaryID,AID) counts
from mytable
) x
Where counts>1
This code cannot be executed, showed an error like
column "o.total_amt_usd" must appear in the GROUP BY clause or be used in an aggregate function
SELECT a.name, MIN(o.total_amt_usd)
FROM accounts a
JOIN orders o ON a.id = o.account_id
GROUP BY a.name
ORDER BY o.total_amt_usd
LIMIT 3
But after I use an alias, it worked:
SELECT a.name, MIN(o.total_amt_usd) small
FROM accounts a
JOIN orders o ON a.id = o.account_id
GROUP BY a.name
ORDER BY small
LIMIT 3
Could anybody explain a little bit about this, please?
Both logically make sense to me. But one of them is not working.
Thanks a lot.
You can't order by o.total_amt_usd since it's not available in the result set (after grouping on name).
You need to order by a grouped field or using an aggregate function like MIN. In this case you'll want to order by MIN(o.total_amt_usd) which is essentially what you are doing after using the alias in the order-clause.
Think about what you're asking of the first query and perhaps try a visual example by hand.
Imagine a table with just 4 rows, John has two rows with amounts of 50 and 20, Bob has two rows with amounts of 30 and 60.
You are asking for each unique name and the corresponding minimum amount, so the results are naturally John:20, Bob:30.
By asking to order your results by referring specfically to every row's Total (and not the aggregated total) you are saying, order my two rows by looking at all four rows, which means John could go both before Bob and after Bob given 20 is less than 30 and 50 is greater than 30.
You might look at the data visually and see the "correct" order, however for the query engine this makes no sense, you can only prioritise the resulting two rows based on their aggregated values, therefore you must order by those aggregated values, either using that column's alias or using the same expression. You cannot order by non-aggregated columns.
I'm having trouble understanding this error through all the researching I have done. I have the following query
SELECT M.[PO Concatenate], Sum(M.SumofAward) AS TotalAward, (SELECT TOP 1 M1.[Material Group] FROM
[MGETCpreMG] AS M1 WHERE M1.[PO Concatenate]=M.[PO Concatenate] ORDER BY M1.SumofAward DESC) AS TopGroup
FROM MGETCpreMG AS M
GROUP BY M.[PO Concatenate];
For a brief instance it reviews the results I want, but then the "At most one record can be returned by this subquery" error comes and wipes all the data to #Name?
For context, [MGETCpreMG] is a query off a main table [MG ETC] that was used to consolidate Award for differing Material Groups on a PO transaction ([PO Concatenate])
SELECT [MG ETC].[PO Concatenate], Sum([MG ETC].Award) AS SumOfAward, [MG ETC].[Material Group]
FROM [MG ETC]
GROUP BY [MG ETC].[PO Concatenate], [MG ETC].[Material Group]
ORDER BY [MG ETC].[PO Concatenate];
I'm thinking it lies in my inability to understand how to utilize a subquery.
In the case in which the query can return more then one value? Simply add an additonal sort by.
So, a common sub query might be to get the last invoice. So you might have:
select ID, CompanyName,
(SELECT TOP 1 InvoiceDate from tblInvoice
where tblInvoice.CustomerID = tblCompany.ID
Order by InvoiceDate DESC)
As LastInvoiceDate
From tblCustomers
Now the above might work for some time, but then it will blow up since you might have two invoices for the same day!
So, all you have to do is add that extra order by clause - say on the PK of the child table like this:
Order by InvoiceDate DESC,ID DESC)
So top 1 will respect the "additional" order columns you add, and thus only ever return one row - even if there are multiple values that match the top 1 column.
I suppose in the above we could perhaps forget the invoiceDate and always take the top most last autonumber ID, but for a lot of queries, you can't always be sure - it might be we want the last most expensive invoice amount. And again, if the max value (top) was the same for two large invoice amounts, then again two rows could be return. So, simply add the extra ORDER BY clause with an 2nd column that further orders the data. And thus top 1 will only pull the first value. Your example of a top group is such an example. Just tack on the extra order by "ID" or whatever the auto number ID column is.
On a report builder 3.0, i retreived some items and counted them using a Count aggregate. Now i want to order them from highest to lowest. How do i use the ORDER BY function on the aggregated column? The picture below show the a column that i want to ORDER BY it, it is ticked.
Pic
The code is vers simple as shown bellow:
SELECT DISTINCT act_id,NameOfAct,
FROM Acts
Your picture indicates you also want a Total row at the bottom:
SELECT
COALESCE(NameOfAct,'Total') NameOfAct,
COUNT(DISTINCT act_id) c
FROM Acts
GROUP BY ROLLUP(NameOfAct)
ORDER BY
CASE WHEN NameOfAct is null THEN 1 ELSE 0 END,
c DESC;
Result of example data:
NameOfAct count
-------------- -------
Act_B 3
Act_A 2
Act_Z 1
Total 6
Try it with example rows at: http://sqlfiddle.com/#!18/dbd6c/2
I looked at the Pic. So you might have duplicate acts with the same name. And you want to know the number of acts that have the same unique name.
You might want to group the results by name:
GROUP BY NameOfAct
And include the act names and their counts in the query results:
SELECT NameOfAct, COUNT(*) AS ActCount
(Since the act_id column is not included in the groups, you need to omit it in the SELECT. The DISTINCT is also not necessary anymore, since all groups are unique already.)
Finally, you can sort the data (probably descending to get the acts with the largest count on top):
ORDER BY ActCount DESC
Your complete query would become something like this:
SELECT NameOfAct, COUNT(*) AS ActCount
FROM Acts
GROUP BY NameOfAct
ORDER BY ActCount DESC
Edit:
By the way, you use field "act_id" in your SELECT clause. That's somewhat confusing. If you want to know counts, you want to look at either the complete table data or group the table data into smaller groups (with the GROUP BY clause). Then you can use aggregate functions to get more information about those groups (or the whole table), like counts, average values, minima, maxima...
Single record information, like an act's ID in your case, is typically not important if you want to use statistic/aggregate methods on grouped data. Suppose your query returns an act name which is used 10 times. Then you have 10 records in your table, each with a unique act_id, but with the same name.
If you need just one act_id that represents each group / act name (and assuming act_id is an autonumbering field), you might include the latest / largest act_id value in the query using the MAX aggregate function:
SELECT NameOfAct, COUNT(*) AS ActCount, MAX(act_id) AS LatestActId
(The rest of the query remains the same.)
Say that I have some SELECT statement:
SELECT id, name FROM people
ORDER BY name ASC;
I have a few million rows in the people table and the ORDER BY clause can be much more complex than what I have shown here (possibly operating on a dozen columns).
I retrieve only a small subset of the rows (say rows 1..11) in order to display them in the UI. Now, I would like to solve following problems:
Find the number of a row with a given id.
Display the 5 items before and the 5 items after a row with a given id.
Problem 2 is easy to solve once I have solved problem 1, as I can then use something like this if I know that the item I was looking for has row number 1000 in the sorted result set (this is the Firebird SQL dialect):
SELECT id, name FROM people
ORDER BY name ASC
ROWS 995 TO 1005;
I also know that I can find the rank of a row by counting all of the rows which come before the one I am looking for, but this can lead to very long WHERE clauses with tons of OR and AND in the condition. And I have to do this repeatedly. With my test data, this takes hundreds of milliseconds, even when using properly indexed columns, which is way too slow.
Is there some means of achieving this by using some SQL:2003 features (such as row_number supported in Firebird 3.0)? I am by no way an SQL guru and I need some pointers here. Could I create a cached view where the result would include a rank/dense rank/row index?
Firebird appears to support window functions (called analytic functions in Oracle). So you can do the following:
To find the "row" number of a a row with a given id:
select id, row_number() over (partition by NULL order by name, id)
from t
where id = <id>
This assumes the id's are unique.
To solve the second problem:
select t.*
from (select id, row_number() over (partition by NULL order by name, id) as rownum
from t
) t join
(select id, row_number() over (partition by NULL order by name, id) as rownum
from t
where id = <id>
) tid
on t.rownum between tid.rownum - 5 and tid.rownum + 5
I might suggest something else, though, if you can modify the table structure. Most databases offer the ability to add an auto-increment column when a row is inserted. If your records are never deleted, this can server as your counter, simplifying your queries.