Hope someone can help.
I have been trying a few queries but I do not seem to be getting the desired result.
I need to identify the highest ‘’claimed’’ users within my table without discarding the columns from the final report.
The user can have more than one record in the table, however the data will be completely different as only the user will match.
The below query only provides me the count per user without giving me the details.
SELECT User, count (*) total_record
FROM mytable
GROUP BY User
ORDER BY count(*) desc
Table:
mytable
Column 1 = User Column 2 = Ref Number Column 3 = Date
The first column will be the unique identifier, however the data in the other columns will differ, therefore it needs to descend the highest claimed user with all the relevant rows to the user to the least claimed user.
User|Ref Num|Date
1|a|20150317
1|b|20150317
2|c|20150317
3|d|20150317
4|e|20150317
1|f|20150317
4|e|20150317
The below data is how the values should be returned.
User|Ref Num|Date|Count
1|a|20150317|3
1|b|20150317|3
1|f|20150317|3
2|c|20150317|1
3|d|20150317|1
4|e|20150317|2
4|e|20150317|2
Hope it makes sense.
Thank you
As you're using MSSQL you can use the OVER() clause like so:
SELECT [user], mt.ref_num, mt.[date], COUNT(mt.[user]) OVER(PARTITION BY mt.[user])
FROM myTable mt
More about the OVER clause can be found here: https://msdn.microsoft.com/en-us/library/ms189461.aspx
As per your comment you can use the wildcard * like so:
SELECT mt.*, COUNT(mt.[user]) OVER(PARTITION BY mt.[user])
FROM myTable mt
This would get you every column as well as the result of the count.
If you want to order by the number of record for each user, then use window functions instead of aggregation:
SELECT t.*
FROM (SELECT t., count(*) OVER (partition by user) as cnt
FROM mytable t
) t
ORDER BY cnt DESC, user;
Note that I added user to the order by so users with the same count will appear together in the list.
You could use an outer apply if your version of SQL Server supports it:
SELECT [User], [Ref Num], Date, total_record
FROM mytable M
OUTER APPLY (
SELECT count(*) total_record
FROM mytable
WHERE [user] = M.[user]
GROUP BY [user]
) oa
ORDER BY total_record desc, [user]
Note that user is a reserved keyword in MSSQL and you need to enclose it in either brackets [user] or double-quotes "user".
This would produce an output like:
user Ref Num Date total_record
1 a 2015-03-17 3
1 b 2015-03-17 3
1 f 2015-03-17 3
4 e 2015-03-17 2
4 e 2015-03-17 2
2 c 2015-03-17 1
3 d 2015-03-17 1
Note that the answers using the count(*) OVER (partition by [user]) construct are more efficient though.
Most simple way would be to use window fuction.
SELECT table.*, COUNT(*) OVER (PARTITION BY user)
FROM nameoftable table -- this is an alias
ORDER BY user, ref_num
This also seem to fit your need.
This is the old way of doing it. Where possible you should use OVER but as other people have answered with that I thought I'd throw this one into the mix.
SELECT
T.[User]
,T.[Ref Num]
,T.[Date]
,(SELECT count(*) from [myTable] T2 where T2.[User] = T.[USER]) as [Count]
FROM [mytable] T
ORDER BY [Count] DESC
Related
I want to get unique CID's from this table. If there are 2 logins I still want to get only 1 row. Here is my code so far:
SELECT distinct [s1FirstName]
,[s1MiddleName]
,[s1LastName]
, [s1CIDNumber]
,Login_Name
FROM [dbSuppHousing].[dbo].[tblSurvey] s
where s.survey_dt>='1/1/1'
AND
s.survey_dt<='1/1/2099'
AND
s1CIDNumber<>''
The problem with above code is it will return multiple rows for different Login_Names. I just want to show 1 Login_Name per unique CID.
order by s1CIDNumber
I believe I need a self join but I cannot figure it out.
with x as
(select row_number() over(partition by s1CIDNumber order by Suevey_DT) as rn, *
from [dbSuppHousing].[dbo].[tblSurvey])
select x.* --add any other columns from tblusers as needed
from x join tblUsers t
on t.loginname = x.loginname
where x.rn = 1
You can use a row_number() function to only select 1 row per login. You can change the partitioning and order conditions if needed.
I am trying to find a query that would give me a count of another table in the query. The problem is that I have no idea what to set where in the count part to. As it is now it will just give back a count of all the values in that table.
Select
ID as Num,
(select Count(*) from TASK where ID=ID(Also tried Num)) as Total
from ORDER
The goal is to have a result that reads like
Num Total
_________________
1 13
2 5
3 22
You need table aliases. So I think you want:
Select ID as Num,
(select Count(*) from TASK t where t.ID = o.ID) as Total
from ORDER o;
By the way, ORDER is a terrible name for a table because it is a reserved work in SQL.
You can do it as a sub query or a join (or an OVER statement.)
I think the join is clearest when you are first learning SQL
Select
ID as Num, count(TASK.ID) AS Total
from ORDER
left join TASK ON ORDER.ID=TASK.ID
GROUP BY ORDER.ID
I'm trying to select the latest date and group by name and keep other columns.
For example:
name status date
-----------------------
a l 13/19/04
a n 13/09/05
a dd 13/18/03
b l 13/01/01
b dd 13/01/02
b n 13/01/03
and I want the result like:
name status date
-----------------
a n 13/09/05
b n 13/01/03
Here's my code
SELECT
Name,
MAX(DATE) as Date,
Status
FROM
[ST].[dbo].[PS_RC_STATUS_TBL]
GROUP BY
Name
I know that I should put max(status) because There are a lot of possibilities in each case, and nothing in the query makes it clear which value to choose for status in each group. Is there anyway to use inner join ?
It's not clear to me you want the max or min status. Rather it seems to me you want the name and status as of a date certain. That is, you want the rows with the lastest date for each name. So ask for that:
select * from PS_RC_STATUS_TBL as T
where exists (
select 1 from PS_RC_STATUS_TBL
where name = T.name
group by name
having max(date) = T.date
)
Another way to think about it is
select T.*
from PS_RC_STATUS_TBL as T
join (
select name, max(date) as date
from PS_RC_STATUS_TBL
group by name
) as D
on T.name = D.name
and T.date = D.date
SQL Server needs to know what to do with the rows that you are not grouping on (it has multiple rows to show on 1 line - so how?). If you have aggregated on them (MIN, MAX, AVG, etc) then you are telling it what to do with these rows. If not it will not know what to do - and will give you an error like the one you are getting.
From what you are saying though - it sounds like you do not want to group by the status. It sounds like you are not interested in that column at all. Let me know If that assumption is wrong.
SELECT
Name,
MAX(Date) AS 'Date',
FROM
PS_RC_STATUS_TBL
GROUP BY
Name
If you really do want the status, but don't want to group on it - try this:
SELECT
MyTable1.Name,
MyTable2.Status,
MyTable1.Date
FROM
(SELECT Name, MAX(Date) AS 'Date' FROM PS_RC_STATUS_TBL GROUP BY Name) MyTable1
INNER JOIN
(SELECT Name, Date, Status FROM PS_RC_STATUS_TBL) MyTable2
ON MyTable1.Name = MyTable2.Name
AND MyTable1.Date = MyTable2.Date
That gives the exact results you've asked for - so does the method below using a CTE.
OR
WITH cte AS (
SELECT Name, MAX(Date) AS Date
FROM PS_RC_STATUS_TBL
GROUP BY Name)
SELECT cte.Name,
tbl.Status,
cte.Date
FROM cte INNER JOIN
PS_RC_STATUS_TBL tbl ON cte.Name = tbl.Name
AND cte.Date = tbl.Date
SQLFiddle example.
It just means that you need to put all non-aggregated columns in the GROUP BY clause, so in the case you need to put the other one
Select Name ,
MAX(DATE) as Date ,
Status
FROM [ST].[dbo].[PS_RC_STATUS_TBL] PS
Group by Name, Status
This is a common problem with text fields in SQL aggregation scenarios. Using either MAX(Status) or MIN(Status) in your field list is a solution, usually MAX(Status) because of the lexical ordering:
"" < " " < "a"
In cases where you really need a more detailed ordering:
Join to a StatusOrder relation (*Status, OrderSequence) in your main query;
select Max(OrderSequence) in your aggregated query; and
Join back to your StatusOrder relation on OrderSequence to select the correct Status value for display.
Whatever fields you're selecting other than aggregation function, need to mention in group by clause.
SELECT
gf.app_id,
ma.name as name,
count(ma.name) as count
FROM [dbo].[geo_fen_notification_table] as gf
inner join dbo.mobile_applications as ma on gf.app_id = ma.id
GROUP BY app_id,name
Here im accessing app_id and name in select, so i need to mention that after group by clause. otherwise it will throw error.
This is a simple problem, and I'm not sure if its possible here. Here's the problem:
=> http://sqlfiddle.com/#!12/584f1/7
Explanation:
A ticket belongs to an attendee
An attendee has a revenue
I need to group the tickets by section and get the total revenue.
This double counts attendees because 2 tickets can belong to the same attendee, thus double counting it. I'd like to grab the sum of the revenue, but only count the attendees once.
In my sqlfiddle example, I'd like to see:
section | total_revenue
------------------------
A | 40 <= 40 is correct, but I'm getting 50...
B | null
C | 40
I'd like to solve this without the use of sub queries. I need a scalable solution that will allow me to do this for multiple columns on different joins in a single query. So whatever allows me to accomplish this, I'm open to suggestions.
Thanks for your help.
Here is a version using row_number():
select section,
sum(revenue) Total
from
(
select t.section, a.revenue,
row_number() over(partition by a.id, t.section order by a.id) rn
from tickets t
left join attendees a
on t.attendee_id = a.id
) src
where rn = 1
group by section
order by section;
See SQL Fiddle with Demo
Again, without subquery:
Key element is to add PARTITION BY to the window function(s):
SELECT DISTINCT
t.section
-- ,sum(count(*)) OVER (PARTITION BY t.section) AS tickets_count
,sum(min(a.revenue)) OVER (PARTITION BY t.section) AS atendees_revenue
FROM tickets t
LEFT JOIN attendees a ON a.id = t.attendee_id
GROUP BY t.attendee_id, t.section
ORDER BY t.section;
-> sqlfiddle
Here, you GROUP BY t.attendee_id, t.section, before you run the result through the window function. And use PARTITION BY t.section in the window function as you want results partitioned by section this time.
Uncomment the second line if you want to get a count of tickets, too.
Otherwise, it works similar to my answer to your previous question. I.e., the rest of the explanation applies.
You can do this:
select t.section, sum(d.revenue)
from
(
SELECT DISTINCT section, attendee_id FROM tickets
) t
left join attendees d on t.attendee_id = d.id
group by t.section
order by t.section;
If I have a table with columns id, name, score, date
and I wanted to run a sql query to get the record where id = 2 with the earliest date in the data set.
Can you do this within the query or do you need to loop after the fact?
I want to get all of the fields of that record..
If you just want the date:
SELECT MIN(date) as EarliestDate
FROM YourTable
WHERE id = 2
If you want all of the information:
SELECT TOP 1 id, name, score, date
FROM YourTable
WHERE id = 2
ORDER BY Date
Prevent loops when you can. Loops often lead to cursors, and cursors are almost never necessary and very often really inefficient.
SELECT TOP 1 ID, Name, Score, [Date]
FROM myTable
WHERE ID = 2
Order BY [Date]
While using TOP or a sub-query both work, I would break the problem into steps:
Find target record
SELECT MIN( date ) AS date, id
FROM myTable
WHERE id = 2
GROUP BY id
Join to get other fields
SELECT mt.id, mt.name, mt.score, mt.date
FROM myTable mt
INNER JOIN
(
SELECT MIN( date ) AS date, id
FROM myTable
WHERE id = 2
GROUP BY id
) x ON x.date = mt.date AND x.id = mt.id
While this solution, using derived tables, is longer, it is:
Easier to test
Self documenting
Extendable
It is easier to test as parts of the query can be run standalone.
It is self documenting as the query directly reflects the requirement
ie the derived table lists the row where id = 2 with the earliest date.
It is extendable as if another condition is required, this can be easily added to the derived table.
Try
select * from dataset
where id = 2
order by date limit 1
Been a while since I did sql, so this might need some tweaking.
Using "limit" and "top" will not work with all SQL servers (for example with Oracle).
You can try a more complex query in pure sql:
select mt1.id, mt1."name", mt1.score, mt1."date" from mytable mt1
where mt1.id=2
and mt1."date"= (select min(mt2."date") from mytable mt2 where mt2.id=2)