Let's say there is a result set...I need to print it out like so:
ID Count
1 5
1 5
1 5
1 5
1 5
2 2
2 2
3 1
Thanks in advance.
Do you mean that your query:
SELECT ID, COUNT(*) AS "Count"
FROM tableX
GROUP BY ID ;
produces this:
ID Count
1 5
2 2
3 1
but you want this?:
ID Count
1 5
1 5
1 5
1 5
1 5
2 2
2 2
3 1
Then, this query will do:
SELECT grp.ID, grp."Count"
FROM
tableX AS t
JOIN
( SELECT ID, COUNT(*) AS "Count"
FROM tableX
GROUP BY ID
) AS grp
ON grp.ID = t.ID ;
It will work in almost all DBMS and in all versions of SQL-Server. For SQL-Server versions 2005 and newer (and also in Oracle and Postgres), the answer with the OVER clause looks more elegant and may be prefered. Test in your version which one is more efficient. I think that in 2012 version, queries with OVER clause are quite efficient.
You can use count() with OVER clause:
select a, count(*) over (partition by a) as [count]
from tableName ;
It's called window function. I recommend you study these.
Related
I have a set of data that I want to classify into groups based on a prior record id existing on the newer rows. The initial record of the group has a prior sequence id = 0.
The data is as follows:
customer id
sequence id
prior_sequence id
1
1
0
1
2
1
1
3
2
2
4
0
2
5
4
2
6
0
2
7
6
Ideally, I would like to create the following grouping column and yield the following results:
customer id
sequence id
prior sequence id
grouping
1
1
0
1
1
2
1
1
1
3
2
1
2
4
0
2
2
5
4
2
2
6
0
3
2
7
6
3
I've attempted to utilize island gap logic utilizing the ROW_NUMBER() function. However, I have been unsuccessful in doing so. I suspect the need here is more along the lines of a recursive CTE, which I am attempting at the moment.
I agree that a recursive CTE will do the job. Something like:
WITH reccte AS
(
/*query that determines starting point for recursion
*
* In this case we want all records with no prior_sequence_id
*/
SELECT
customer_id,
sequence_id,
prior_sequence_id,
/*establish grouping*/
ROW_NUMBER() OVER (ORDER BY sequence_id) as grouping
FROM yourtable
WHERE prior_sequence_id = 0
UNION
/*join the recursive CTe back to the table and iterate*/
SELECT
yourtable.customer_id,
yourtable.sequence_id,
yourtable.prior_sequence_id,
reccte.grouping
FROM reccte
INNER JOIN yourtable ON reccte.sequence_id = yourtable.prior_sequence_id
)
SELECT * FROM reccte;
It looks like you could use a simple correlated query, at least given your sample data:
select *, (
select Sum(Iif(prior_sequence_id = 0, 1, 0))
from t t2
where t2.sequence_id <= t.sequence_id
) Grouping
from t;
See Example Fiddle
Please see fiddle: http://sqlfiddle.com/#!6/e6768/2
I have data, like below:
DRIVER DROP
1 1
1 2
1 ReturnToBase
1 4
1 5
1 ReturnToBase
1 6
1 7
2 1
2 2
2 ReturnToBase
2 4
I am trying to group my data, so for each driver, each group of return to bases have a grouping number.
My output should look like this:
DRIVER DROP GROUP
1 1 1
1 2 1
1 ReturnToBase 1
1 4 2
1 5 2
1 ReturnToBase 2
1 6 3
1 7 3
1 ReturnToBase 3
2 1 1
2 2 1
2 ReturnToBase 1
2 4 2
I've tried getting this result with a combination of windowed functions but I've been miles off so far
Below is what I had so far, it isn't supposed to be functional I was trying to figure out how it could be done, if it's even possible.
SELECT
ROW_NUMBER() OVER (Partition BY Driver order by Driver Desc) rownum,
Count(1) OVER (Partition By Driver Order By Driver Desc) counter,
Count
DropNo,
Driver,
CASE DropNo
WHEN 'ReturnToBase' THEN 1 ELSE 0 END AS EnumerateRound
FROM
Rounds
You can use the following query:
SELECT id, DRIVER, DROPno,
1 + SUM(flag) OVER (PARTITION BY DRIVER ORDER BY id) -
CASE
WHEN DROPno = 'ReturnToBase' THEN 1
ELSE 0
END AS grp
FROM (
SELECT id, DRIVER, DROPno,
CASE
WHEN DROPno = 'ReturnToBase' THEN 1
ELSE 0
END AS flag
FROM rounds ) AS t
Demo here
This query uses windowed version of SUM with ORDER BY in the OVER clause to calculate a running total. This version of SUM is available from SQL Server 2012 onwards AFAIK.
Fiddling a bit with this running total value is all we need in order to get the correct GROUP value.
EDIT: (credit goes to #Conrad Frix)
Using CROSS APPLY instead of an in-line view can considerably simplify things:
SELECT id, DRIVER, DROPno,
1 + SUM(x.flag) OVER (PARTITION BY DRIVER ORDER BY id) - x.flag
FROM rounds
CROSS APPLY (SELECT CASE WHEN DROPno = 'ReturnToBase' THEN 1 ELSE 0 END) AS x(flag)
Demo here
Added a sequential ID column to your example for use in a recursive CTE:
with cte as (
select ID,DRIVER,DROPno,1 as GRP
FROM rounds
where ID = 1
union all
select a.ID
,a.DRIVER
,a.DROPno
,case when b.DROPno = 'ReturnToBase'
or b.DRIVER <> a.DRIVER then b.GRP + 1
else b.GRP end
from rounds a
inner join cte b
on a.ID = b.ID + 1
)
select * from cte
SQL Fiddle
In my SQl server Sp.
`SELECT rating as [Rating],count(id) as [RatingCount]
FROM MMBPollResults
where mmb_id = #MMbid
GROUP BY rating
This SP returns the rating for each user.
i:e rating ratingcount
` 1 2
2 1
5 4
So this means that
2users have rated the transaction with 1star
1 user has rated the transaction with 2stars
4 users have rated the transaction with 5stars
This is how I need the output
rating ratingcount
` 1 2
2 1
3 0
4 0
5 4
Sorry, if this is a silly question
Thanks
Sun
You need a table with 1 to 5. This could be a number table or some other rating table.
Here I use a simple UNION to make a table with 1 to 5
SELECT
List.Rating,
count(MMB.*) as [RatingCount]
FROM
(
SELECT 1 AS Rating
UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5
) List
LEFT JOIN
MMBPollResults MMB ON List.Rating = MMB.Rating AND MMB.mmb_id = #MMbid
GROUP BY
List.Rating
ORDER BY
List.Rating;
I have a temp table which has two columns: one is Name and another RecordNumber. They looks like below:
Name RecordNumber Rownum
EMEA-1111-SCHD-1 0 1
EMEA-12362-SCHD-1 0 2
EMEA-12362-SCHD-1 0 3
EMEA-12362-SCHD-1 0 4
EMEA-12362-SCHD-1 0 5
EMEA-2191-SCHD-1 0 6
EMEA-2191-SCHD-1 0 7
EMEA-2191-SCHD-1 0 8
I need to update column "RecordNumber" with increment number starting with 1. Let say for EMEA-1111-SCHD-1 only one record, so RecordNumber should be updated to 1. For EMEA-12362-SCHD-1 four records, so RecordNumber should be updated to 1,2,3,4 accordingly. Basically, I need to have a result as:
Name RecordNumber Rownum
EMEA-1111-SCHD-1 1 1
EMEA-12362-SCHD-1 1 2
EMEA-12362-SCHD-1 2 3
EMEA-12362-SCHD-1 3 4
EMEA-12362-SCHD-1 4 5
EMEA-2191-SCHD-1 1 6
EMEA-2191-SCHD-1 2 7
EMEA-2191-SCHD-1 3 8
Is it possible to do it without cursor?
Thank you, Ed.
I added identity col rownum to make this records unique. Is any idea how to update result to have record number by group?
You could do this query only in Sybase IQ with analytical functions.
http://infocenter.sybase.com/help/index.jsp?topic=/com.sybase.infocenter.dc38151.1510/html/iqrefbb/BCGEEBHA.htm
I have't access to sybase IQ this time, so I can't check query, but I suppose the right query is something like
select name,
row_number() over (partition by name) as RecordNumber
from Table
AFAIK Sybase ASE has't this feature.
Update
I think you can create self join query like this
select t1.name,
t1.Rownum - t2.MinRowNum + 1
from Table as t1,
(select name, min (Rownum) as MinRowNum from Table group by name) as t2
where t1.name = t2.name
order by t1.name, t1.Rownum
I would like to filter duplicate rows on conditions so that the rows with minimum modified and maximum active and unique rid and did are picked. self join? or any better approach that would be performance wise better?
Example:
id rid modified active did
1 1 2010-09-07 11:37:44.850 1 1
2 1 2010-09-07 11:38:44.000 1 1
3 1 2010-09-07 11:39:44.000 1 1
4 1 2010-09-07 11:40:44.000 0 1
5 2 2010-09-07 11:41:44.000 1 1
6 1 2010-09-07 11:42:44.000 1 2
Output expected is
1 1 2010-09-07 11:37:44.850 1 1
5 2 2010-09-07 11:41:44.000 1 1
6 1 2010-09-07 11:42:44.000 1 2
Commenting on the first answer, the suggestion does not work for the below dataset(when active=0 and modified is the minimum for that row)
id rid modified active did
1 1 2010-09-07 11:37:44.850 1 1
2 1 2010-09-07 11:38:44.000 1 1
3 1 2010-09-07 11:39:44.000 1 1
4 1 2010-09-07 11:36:44.000 0 1
5 2 2010-09-07 11:41:44.000 1 1
6 1 2010-09-07 11:42:44.000 1 2
Assuming SQL Server 2005+. Use RANK() instead of ROW_NUMBER() if you want ties returned.
;WITH YourTable as
(
SELECT 1 id,1 rid,cast('2010-09-07 11:37:44.850' as datetime) modified, 1 active,1 did union all
SELECT 2,1,'2010-09-07 11:38:44.000', 1,1 union all
SELECT 3,1,'2010-09-07 11:39:44.000', 1,1 union all
SELECT 4,1,'2010-09-07 11:36:44.000', 0,1 union all
SELECT 5,2,'2010-09-07 11:41:44.000', 1,1 union all
SELECT 6,1,'2010-09-07 11:42:44.000', 1,2
),cte as
(
SELECT id,rid,modified,active, did,
ROW_NUMBER() OVER (PARTITION BY rid,did ORDER BY active DESC, modified ASC ) RN
FROM YourTable
)
SELECT id,rid,modified,active, did
FROM cte
WHERE rn=1
order by id
select id, rid, min(modified), max(active), did from foo group by rid, did order by id;
You can get good performance with a CROSS APPLY if you have a table that has one row for each combination of rid and did:
SELECT
X.*
FROM
ParentTable P
CROSS APPLY (
SELECT TOP 1 *
FROM YourTable T
WHERE P.rid = T.rid AND P.did = T.did
ORDER BY active DESC, modified
) X
Substituting (SELECT DISTINCT rid, did FROM YourTable) for ParentTable would work but will hurt performance.
Also, here is my crazy, single scan magic query which can often outperform other methods:
SELECT
id = Substring(Packed, 6, 4),
rid,
modified = Convert(datetime, Substring(Packed, 2, 4)),
Active = Convert(bit, 1 - Substring(Packed, 1, 1)),
did,
FROM
(
SELECT
rid,
did,
Packed = Min(Convert(binary(1), 1 - active) + Convert(binary(4), modified) + Convert(binary(4), id)
FROM
YourTable
GROUP BY
rid,
did
) X
This method is not recommended because it's not easy to understand, and it's very easy to make mistakes with it. But it's a fun oddity because it can outperform other methods in some cases.