I have a single table that looks like the following (dumbed down):
userid | action | userstate
-----------------------------------------------------
1 | click | Maryland
2 | press | Delaware
3 | jog | New York
3 | leap | New York
What I'm trying to query is "number of users doing ANY action, per state"
So the result would be:
state | users_acting
---------------------
Maryland | 1
Delaware | 1
New York | 1
Note that individual users will only be part in one state.
I can't get the mix of distinct users correct with grouping by state. I can't
SELECT DISTINCT (userid), COUNT(userid) FROM data GROUP BY state
because the distinct column needs to be in the group by, which I don't want to actually do, not to mention problems w/ the select clause.
Thanks for any thoughts.
Just found out that there's a COUNT(DISTINCT( option which doesn't require that distinct value to be placed in the grouping clause.
SELECT COUNT(DISTINCT userid) FROM data GROUP BY state
Does the trick
You can try out the below format
SELECT COUNT(DISTINCT userid) FROM data GROUP BY state
Related
I'm still very new to MS-SQL. I have a simple table and query that that is getting the best of me. I know it will something fundamental I'm overlooking.
I've changed the field names but the idea is the same.
So the idea is that every time someone signs up they get a RegID, Name, and Team. The names are unique, so for below yes John changed teams. And that's my trouble.
Football Table
+------------+----------+---------+
| Max_RegID | Name | Team |
+------------+----------+---------+
| 100 | John | Red |
| 101 | Bill | Blue |
| 102 | Tom | Green |
| 103 | John | Green |
+------------+----------+---------+
With the query at the bottom using the Max_RegID, I was expecting to get back only one record.
+------------+----------+---------+
| Max_RegID | Name | Team |
+------------+----------+---------+
| 103 | John | Green |
+------------+----------+---------+
Instead I get back below, Which seems to include Max_RegID but also for each team. What am I doing wrong?
+------------+----------+---------+
| Max_RegID | Name | Team |
+------------+----------+---------+
| 100 | John | Red |
| 103 | John | Green |
+------------+----------+---------+
My Query
SELECT
Max(Football.RegID) AS Max_RegID,
Football.Name,
Football.Team
FROM
Football
GROUP BY
Football.RegID,
Football.Name,
Football.Team
EDIT* Removed the WHERE statement
The reason you're getting the results that you are is because of the way you have your GROUP BY clause structured.
When you're using any aggregate function, MAX(X), SUM(X), COUNT(X), or what have you, you're telling the SQL engine that you want the aggregate value of column X for each unique combination of the columns listed in the GROUP BY clause.
In your query as written, you're grouping by all three of the columns in the table, telling the SQL engine that each tuple is unique. Therefore the query is returning ALL of the values, and you aren't actually getting the MAX of anything at all.
What you actually want in your results is the maximum RegID for each distinct value in the Name column and also the Team that goes along with that (RegID,Name) combination.
To accomplish that you need to find the MAX(ID) for each Name in an initial data set, and then use that list of RegIDs to add the values for Name and Team in a secondary data set.
Caveat (per comments from #HABO): This is premised on the assumption that RegID is a unique number (an IDENTITY column, value from a SEQUENCE, or something of that sort). If there are duplicate values, this will fail.
The most straight forward way to accomplish that is with a sub-query. The sub-query below gets your unique RegIDs, then joins to the original table to add the other values.
SELECT
f.RegID
,f.Name
,f.Team
FROM
Football AS f
JOIN
(--The sub-query, sq, gets the list of IDs
SELECT
MAX(f2.RegID) AS Max_RegID
FROM
Football AS f2
GROUP BY
f2.Name
) AS sq
ON
sq.Max_RegID = f.RegID;
EDIT: Sorry. I just re-read the question. To get just the single record for the MAX(RegID), just take the GROUP BY out of the sub-query, and you'll just get the current maximum value, which you can use to find the values in the rest of the columns.
SELECT
f.RegID
,f.Name
,f.Team
FROM
Football AS f
JOIN
(--The sub-query, sq, now gets the MAX ID
SELECT
MAX(f2.RegID) AS Max_RegID
FROM
Football AS f2
) AS sq
ON
sq.Max_RegID = f.RegID;
Use row_number()
select * from
(SELECT
Football.RegID AS Max_RegID,
Football.Name,
Football.Team, row_number() over(partition by name order by Football.RegID desc) as rn
FROM
Football
WHERE
Football.Name = 'John')a
where rn=1
simply you can edit your query below way
SELECT *
FROM
Football f
WHERE
f.Name = 'John' and
Max_RegID = (SELECT Max(Football.Max_RegID) where Football.Name = 'John'
)
or
if sql server simply use this
select top 1 * from Football f
where f.Name = 'John'
order by Max_RegID desc
or
if mysql then
select * from Football f
where f.Name = 'John'
order by Max_RegID desc
Limit 1
You need self join :
select f1.*
from Football f inner join
Football f1
on f1.name = f.name
where f.Max_RegID = 103;
After re-visit question, the sample data suggests me subquery :
select f.*
from Football f
where name = (select top (1) f1.name
from Football f1
order by f1.Max_RegID desc
);
I have a table in Hive containing store names, order IDs, and User IDs (as well as some other columns including item ID). There is a row in the table for every item purchased (so there can be more than one row per order if the order contains multiple items). Order IDs are unique within a store, but not across stores. A single order can have more than one user ID associated with it.
I'm trying to write a query that will return a list of all stores and order IDs and the shortest user ID associated with each order.
So, for example, if the data looks like this:
STORE | ORDERID | USERID | ITEMID
------+---------+--------+-------
| a | 1 | bill | abc |
| a | 1 | susan | def |
| a | 2 | jane | abc |
| b | 1 | scott | ghi |
| b | 1 | tony | jkl |
Then the output would look like this:
STORE | ORDERID | USERID
------+---------+-------
a | 1 | bill
a | 2 | jane
b | 1 | tony
I've written a query that will do this, but I feel like there must be a more efficient way to go about it. Does anybody know a better way to produce these results?
This is what I have so far:
select
users.store, users.orderid, users.userid
from
(select
store, orderid, userid, length(userid) as len
from
sales) users
join
(select distinct
store, orderid,
min(length(userid)) over (partition by store, orderid) as len
from
sales) len on users.store = len.store
and users.orderid = len.orderid
and users.len = len.len
Check out probably this will work for you, here you can achieve your goal of single "SELECT" clause with no extra overhead on SQL.
select distinct
store, orderid,
first_value(userid) over(partition by store, orderid order by length(userid) asc) f_val
from
sales;
The result will be:
store orderid f_val
a 1 bill
a 2 jane
b 1 tony
Probably rank() is the best way:
select s.*
from (select s.*, rank() over (partition by store order by length(userid) as seqnum
from sales s
) s
where seqnum = 1;
So here is my situation:
____________________________________________
| idnumber | name | sectiongroup |
--------------------------------------------
| 123 | Joe | one |
| 123 | Barry | two |
| 1234 | Laura | one |
| 1234 | LauraCopyCat | one |
--------------------------------------------
I am trying to build a query which will return any unique (i.e. - COUNT(idnumber) = 1) id numbers in a given sectiongroup. So if you are in sectiongroup number one and no one else in your sectiongroup has the same ID number as you, then I want your idnumber. If someone in group two happens to have the same idnumer, that is okay, I still want your idnumber.
For example, Barry and Joe have the same id number but they are in separate sectiongroups, so I want to return their idnubers. However, Laura and LauraCopyCat have the SAME sectiongroup, so I do NOT want their idnumbers to be returned. So far I have the following:
SELECT idnumber
FROM namestable
GROUP BY idnumber, sectiongroup
HAVING(COUNT(idnumber) = 1)
Is there a way to add sectiongroup into the COUNT()=1 condition?
Just use COUNT(*) to avoid confusion. This will count the number of records in the particular group. Remember, a group consists of the unique combinations of values in the fields specified in your GROUP BY statement.
SELECT idnumber
FROM namestable
GROUP BY idnumber, sectiongroup
HAVING COUNT(*) = 1
Note that this will result in duplicate idnumbers, if you have records that share an id but have different subgroups. To remove duplicate, just change SELECT to SELECT DISTINCT.
Tested here: http://sqlfiddle.com/#!9/b0a50c/3
So I got this very inconsistent record for example(just an example):
Manager | Associate | FTE | Revenue
Bob | James | Y | 500
Bob | James | NULL | 100
Bob | James | Y | 200
Kelly | Rick | N | 200
Kelly | Rick | N | 500
Kelly | Rick | NULL | 300
So the goal i wanted was to Sum up the revenue, but the problem is in the group by the nulls kinda split them apart. So i want to write an update statement saying basically "well Looks like James and Bob are both FTE, so lets update that to Y and Kelly and rick are not so update that to no."
How can i fix this? Using MSAccess and of course my table is a lot biger with a lot of different name combos.
You can "impute" the value by using an aggregation function. The following query aggregates by manager/associate and takes the maximum value of fte. This is then joined back to the original data to do the calculation:
select ma.fte, sum(Revenue)
from table as t inner join
(select manager, associate, max(fte) as fte
from table as t
group by manager, associate
) as ma
on t.manager = ma.manager and
t.associate = ma.associate
group by ma.fte;
EDIT:
Immediately after posting this, I realized the join is not necessary. Two aggregations are sufficient:
select ma.fte, sum(Revenue)
from (select manager, associate, max(fte) as fte, sum(Revenue) as Revenue
from table as t
group by manager, associate
) as ma
group by ma.fte;
You haven't given the primary key columns, which makes it a bit harder. I've called it {id} below.
With the nulls, many SQL dialects have an "IfNull" function, but it seems MS-Access does not. You can get the same effect this way:
IIF(ISNULL(column),0,column)
You'd use that in a SELECT as so:
SELECT IIF(ISNULL(Revenue),0,Revenue) FROM ...
For a one-off fix you could do this:
UPDATE {table} SET Revenue=0 WHERE Revenue = NULL;
Doing a join to get the FTE from another row is more complex, and I don't have access handy to see just what the limits and syntax are. The easy to understand way is a nested query:
UPDATE {table} a SET FTE = (SELECT max(FTE) FROM {table} b WHERE FTE IS NOT NULL AND a.{id} = b.{id})
The max() function works here because it ignores nulls, where some other functions return null if you pass a null in.
Need help with Min Function in SQL
I have a table as shown below.
+------------+-------+-------+
| Date_ | Name | Score |
+------------+-------+-------+
| 2012/07/05 | Jack | 1 |
| 2012/07/05 | Jones | 1 |
| 2012/07/06 | Jill | 2 |
| 2012/07/06 | James | 3 |
| 2012/07/07 | Hugo | 1 |
| 2012/07/07 | Jack | 1 |
| 2012/07/07 | Jim | 2 |
+------------+-------+-------+
I would like to get the output like below
+------------+------+-------+
| Date_ | Name | Score |
+------------+------+-------+
| 2012/07/05 | Jack | 1 |
| 2012/07/06 | Jill | 2 |
| 2012/07/07 | Hugo | 1 |
+------------+------+-------+
When I use the MIN() function with just the date and Score column I get the lowest score for each date, which is what I want. I don't care which row is returned if there is a tie in the score for the same date. Trouble starts when I also want name column in the output. I tried a few variation of SQL (i.e min with correlated sub query) but I have no luck getting the output as shown above. Can anyone help please:)
Query is as follows
SELECT DISTINCT
A.USername, A.Date_, A.Score
FROM TestTable AS A
INNER JOIN (SELECT Date_,MIN(Score) AS MinScore
FROM TestTable
GROUP BY Date_) AS B
ON (A.Score = B.MinScore) AND (A.Date_ = B.Date_);
Use this solution:
SELECT a.date_, MIN(name) AS name, a.score
FROM tbl a
INNER JOIN
(
SELECT date_, MIN(score) AS minscore
FROM tbl
GROUP BY date_
) b ON a.date_ = b.date_ AND a.score = b.minscore
GROUP BY a.date_, a.score
SQL-Fiddle Demo
This will get the minimum score per date in the INNER JOIN subselect, which we use to join to the main table. Once we join the subselect, we will only have dates with names having the minimum score (with ties being displayed).
Since we only want one name per date, we then group by date and score, selecting whichever name: MIN(name).
If we want to display the name column, we must use an aggregate function on name to facilitate the GROUP BY on date and score columns, or else it will not work (We could also use MAX() on that column as well).
Please learn about the GROUP BY functionality of RDBMS.
SELECT Date_,Name,MIN(Score)
FROM T
GROUP BY Name
This makes the assumption that EACH NAME and EACH date appears only once, and this will only work for MySQL.
To make it work on other RDBMSs, you need to apply another group function on the Date column, like MAX. MIN. etc
SELECT T.Name, T.Date_, MIN(T.Score) as Score FROM T
GROUP BY T.Date_
Edit: This answer is not corrected as pointed out by JNK in comments
SELECT Date_,MAX(Name),MIN(Score)
FROM T
GROUP BY Date_
Here I am using MAX(NAME), it will pick one name if two names were found with the same goal numbers.
This will find Min score for each day (no duplicates), scored by any player. The name that starts with Z will be picked first than the name that starts with A.
Edit: Fixed by removing group by name