The same client can have multiple decision numbers, I need to choose the max of multiple the decision number. Please help.
sample data
CNO DNO
1 1
1 2
3 3
You can use window function like:
max(decisionNumber) over (partition by ClientName) as 'MAXofDecisionNumber'
SELECT DECNO,MAX(CNO) FROM TABLE1 GROUP BY DECNO
FOR BOTH MAX
SELECT DECNO,MAX(CNO) FROM TABLE1
WHERE DECNO = (SELECT MAX(DECNO) FROM TABLE1)
GROUP BY DECNO
Live Demo
http://sqlfiddle.com/#!18/3cdd0/3
Related
I have been attempting the following query for a while- not sure how to approach this issue I'm having.
I need to obtain bands that cover the second most styles of music - including all equal bands if there is a tie for second. For example for the table band_style,
Band_id | Style
---------------------
1 Rock
2 Pop
1 Punk
3 Classical
1 Metal
2 Rock
4 Pop
4 Rap
The returned result should be
Band_id | Num_styles
2 2
4 2
My initial attempt at a solution:
SELECT band_id, COUNT(*) AS num_styles FROM band_style
GROUP BY band_id HAVING COUNT(*) <
(SELECT MAX(c) FROM
(SELECT COUNT(band_id) AS c
FROM band_style
GROUP BY band_id));
So this gives me the count of all the bands with less styles than the maximum. Now, I'd like to take ALL rows which have the maximum value of this query. I do not want to use rownum or limit because from what I've experienced this doesn't work too well in the case of ties. I am also wondering if there is a way to wrap this in another MAX function, but I don't really see how.
Any help with this issue would be appreciated- also think this would be useful to know to see if it can be applied to 3rd, 4th highest, etc.
(Using Oracle/SQLPlus)
Assuming this is a large data file and we do not necessarily know what the "second highest count" is.
UPDATE: this almost works- gets all bands with less than max number of styles. But calling MAX doesn't seem to be working, as the table returned still has all values of NUM except the max..
WITH data AS (
SELECT band_id, COUNT(*) AS NUM FROM band_style GROUP BY band_id HAVING COUNT (*) <
(SELECT MAX(c) FROM
(SELECT COUNT(band_id) AS c
FROM band_style
GROUP BY band_id)))
SELECT data.band_id, data.NUM FROM data
INNER JOIN ( SELECT band_id m, MAX(NUM) n
FROM data GROUP BY band_id
) t
ON t.band_id = data.band_id
AND t.NUM = data.NUM;
If you have to stick with mysql, this sql will be much more difficult. But if you could switch to mariadb or oracle this should work.
with data as (
select
band_id, count(*) styles,
dense_rank() over (order by count(*) desc) place
from
table1 group by band_id)
select * from data where place=2
http://sqlfiddle.com/#!4/dc3f6/12
Your friend here is the window function dense_rank.
The output is:
BAND_ID STYLES PLACE
2 2 2
4 2 2
And here to avoid some missunderstandings, due to place 2 is here styles 2.
http://sqlfiddle.com/#!4/2be32/3
Now the styles count is different from the place id.
BAND_ID STYLES PLACE
4 3 2
This illustrates that dense_rank does not know the second highest count value beforehand.
I have a table that looks like the following but also has more columns that are not needed for this instance.
ID DATE Random
-- -------- ---------
1 4/12/2015 2
2 4/15/2015 2
3 3/12/2015 2
4 9/16/2015 3
5 1/12/2015 3
6 2/12/2015 3
ID is the primary key
Random is a foreign key but i am not actually using table it points to.
I am trying to design a query that groups the results by Random and Date and select the MAX Date within the grouping then gives me the associated ID.
IF i do the following query
select top 100 ID, Random, MAX(Date) from DateBase group by Random, Date, ID
I get duplicate Randoms since ID is the primary key and will always be unique.
The results i need would look something like this
ID DATE Random
-- -------- ---------
2 4/15/2015 2
4 9/16/2015 3
Also another question is there could be times where there are many of the same date. What will MAX do in that case?
You can use NOT EXISTS() :
SELECT * FROM YourTable t
WHERE NOT EXISTS(SELECT 1 FROM YourTable s
WHERE s.random = t.random
AND s.date > t.date)
This will select only those who doesn't have a bigger date for corresponding random value.
Can also be done using IN() :
SELECT * FROM YourTable t
WHERE (t.random,t.date) in (SELECT s.random,max(s.date)
FROM YourTable s
GROUP BY s.random)
Or with a join:
SELECT t.* FROM YourTable t
INNER JOIN (SELECT s.random,max(s.date) as max_date
FROM YourTable s
GROUP BY s.random) tt
ON(t.date = tt.max_date and s.random = t.random)
In SQL Server you could do something like the following,
select a.* from DateBase a inner join
(select Random,
MAX(dt) as dt from DateBase group by Random) as x
on a.dt =x.dt and a.random = x.random
This method will work in all versions of SQL as there are no vendor specifics (you'll need to format the dates using your vendor specific syntax)
You can do this in two stages:
The first step is to work out the max date for each random:
SELECT MAX(DateField) AS MaxDateField, Random
FROM Example
GROUP BY Random
Now you can join back onto your table to get the max ID for each combination:
SELECT MAX(e.ID) AS ID
,e.DateField AS DateField
,e.Random
FROM Example AS e
INNER JOIN (
SELECT MAX(DateField) AS MaxDateField, Random
FROM Example
GROUP BY Random
) data
ON data.MaxDateField = e.DateField
AND data.Random = e.Random
GROUP BY DateField, Random
SQL Fiddle example here: SQL Fiddle
To answer your second question:
If there are multiples of the same date, the MAX(e.ID) will simply choose the highest number. If you want the lowest, you can use MIN(e.ID) instead.
In MS Access, I have a table with 2 million account records/rows with various columns of data. I wish to apply a sequence number to every account record. (i.e.- 1 for the first account record ABC111, 2 for the second account record DEF222..., etc.)
Then, I would like to assign a batch number sequence for every 5 distinct account number. (i.e - record 1 with account number ABC111 being associated with batch number 101, record 2 with account number DEF222 being associated with batch number of 101)
This is how I would do it with a sql server query:
select distinct(p.accountnumber),FLOOR(((50 + dense_rank() over(order by
p.accountnumber)) - 1)/5) + 100 As BATCH from
db2inst1.account_table p
Raw Data:
AccountNumber
ABC111
DEF222
GHI333
JKL444
MNO555
PQR666
STU777
Resulting Data:
RecordNumber AccountNumber BatchNumber
1 ABC111 101
2 DEF222 101
3 GHI333 101
4 JKL444 101
5 MNO555 101
6 PQR666 102
7 STU777 102
I tried to make a query that uses SELECT as well as DENSE_RANK but I couldn't figure out how to make it work.
Thanks for reading my question
Something like this would probably work.
I'd first create a temporary table to hold the distinct account numbers, then I'd do an update query to assign the ranking.
CREATE TABLE tmpAccountRank
(AccountNumber TEXT(10)
CONSTRAINT PrimaryKey PRIMARY KEY,
AccountRank INTEGER NULL);
Then I'd use this table to generate the account ranking.
DELETE FROM tmpAccountRank;
INSERT INTO tmpAccountRank(AccountNumber)
SELECT DISTINCT AccountNumber FROM db2inst1.account_table;
UPDATE tmpAccountRank
SET AccountRank =
DCOUNT('AccountNumber', 'tmpAccountRank',
'AccountNumber < ''' + AccountNumber + '''') \ 5 + 101
I use DCOUNT and integer division (\ 5) to generate the ranking. This probably will have terrible performance but I think it's the way you would do it in MS Access.
If you want to skip the temp table, you can do it all in a nested subquery, but I don't think it's a great practice to do too much in a single query, especially in MS Access.
SELECT AccountNumber,
(SELECT COUNT(*) FROM
(SELECT DISTINCT AccountNumber
FROM db2inst1.account_table
WHERE AccountNumber < t.AccountNumber) q)) \ 5 + 101
FROM db2inst1.account_table t
Actually, this won't work in MS Access; apparently you can't reference tables outside of multiple levels of nesting in a subquery.
You can do dense_rank() with a correlated subquery. The logic is:
select a.*,
(select count(distinct a2.accountnumber)
from db2inst1.account_table as a2
where a2.accountnumber <= a.accountnumber
) as dense_rank
from db2inst1.account_table as a;
Then, you can use this for getting the batch number. Unfortunately, I don't follow the logic in your question (dense_rank() produces a number but your batch number is not numeric). However, this should answer your question.
EDIT:
Oh, that's right. In MS Access you need nested subqueries:
select a.*,
(select count(*)
from (select distinct a2.accountnumber
from db2inst1.account_table as a2
) as a2
where a2.accountnumber <= a.accountnumber
) as dense_rank
from db2inst1.account_table as a;
I've been looking for an answer to this but couldn't find anything the same as this particular situation.
So I have a one table that I want to remove duplicates from.
__________________
| JobNumber-String |
| JobOp - Number |
------------------
So there are multiples of these two values, together they make the key for the row. I want keep all distinct job numbers with the lowest job op. How can I do this? I've tried a bunch of things, mainly trying the min function, but that only seems to work on the entire table not just the JobNumber sets. Thanks!
Original Table Values:
JobNumber Jobop
123 100
123 101
456 200
456 201
780 300
Code Ran:
DELETE FROM table
WHERE CONCAT(JobNumber,JobOp) NOT IN
(
SELECT CONCAT(JobNumber,MIN(JobOp))
FROM table
GROUP BY JobNumber
)
Ending Table Values:
JobNumber Jobop
123 100
456 200
780 300
With SQL Server 2008 or higher you can enhance the MIN function with an OVER clause specifying a PARTITION BY section.
Please have a look at https://msdn.microsoft.com/en-us/library/ms189461.aspx
You can simply select the values you want to keep:
select jobOp, min(number) from table group by jobOp
Then you can delete the records you don't want:
DELETE t FROM table t
left JOIN (select jobOp, min(number) as minnumber from table group by jobOp ) e
ON t.jobob = e.jobob and t.number = e.minnumber
Where e.jobob is null
I like to do this with window functions:
with todelete as (
select t.*, min(jobop) over (partition by numbers) as minjop
from table t
)
delete from todelete
where jobop > minjop;
It sounds like you are not using the correct GROUP BY clause when using the MIN function. This sql should give you the minimum JobOp value for each JobNumber:
SELECT JobNumber, MIN(JobOp) FROM test.so_test GROUP BY JobNumber;
Using this in a subquery, along with CONCAT (this is from MySQL, SQL Server might use different function) because both fields form your key, gives you this sql:
SELECT * FROM so_test WHERE CONCAT(JobNumber,JobOp)
NOT IN (SELECT CONCAT(JobNumber,MIN(JobOp)) FROM test.so_test GROUP BY JobNumber);
I am looking for the AVERAGE (overall) of the MINIMUM number (grouped by person).
My table looks like this:
Rank Name
1 Amy
2 Amy
3 Amy
2 Bart
1 Charlie
2 David
5 David
1 Ed
2 Frank
4 Frank
5 Frank
I want to know the AVERAGE of the lowest scores. For these people, the lowest scores are:
Rank Name
1 Amy
2 Bart
1 Charlie
2 David
1 Ed
2 Frank
Giving me a final answer of 1.5 - because three people have a MIN(Rank) of 1 and the other three have a MIN(Rank) of 2. That's what I'm looking for - a single number.
My real data has a couple hundred rows, so it's not terribly big. But I can't figure out how to do this in a single, simple statement. Thank you for any help.
Try this:
;WITH MinScores
AS
(
SELECT
"Rank",
Name,
ROW_NUMBER() OVER(PARTITION BY Name ORDER BY "Rank") row_num
FROM Table1
)
SELECT
CAST(SUM("Rank") AS DECIMAL(10, 2)) /
COUNT("Rank")
FROM MinScores
WHERE row_num = 1;
SQL Fiddle Demo
Selecting the set of minimum values is straightforward. The cast() is necessary to avoid integer division later. You could also avoid integer division by casting to float instead of decimal. (But you should be aware that floats are "useful approximations".)
select name, cast(min(rank) as decimal) as min_rank
from Table1
group by name
Now you can use the minimums as a common table expression, and select from it.
with minimums as (
select name, cast(min(rank) as decimal) as min_rank
from Table1
group by name
)
select avg(min_rank) avg_min_rank
from minimums
If you happen to need to do the same thing on a platform that doesn't support common table expressions, you can a) create a view of minimums, and select from that view, or b) use the minimums as a derived table.
You might try using a derived table to get the minimums, then get the average minimum in the outer query, as in:
-- Get the avg min rank as a decimal
select avg(MinRank * 1.0) as AvgRank
from (
-- Get everyone's min rank
select min([Rank]) as MinRank
from MyTable
group by Name
) as a
I think the easiest one will be
for max
select name , max_rank = max(rank)
from table
group by name;
for average
select name , avg_rank = avg(rank)
from table
cgroup by name;