I have an Address History table with three fields: EmpID, Address, AddrID.
Every time I add a new address, I also increment the Address ID (AddrID) by 1 for that particular employee.
EmpID | AddrID | Address
-------------------------------
1 | 1 | 1234 First Ave
1 | 2 | 2145 First Ave
1 | 3 | 1111 First Ave
2 | 1 | 1001 Second St
2 | 2 | 1002 Second St
2 | 3 | 1003 Second St
2 | 4 | 2222 Second St
3 | 1 | 3332 Third Lane
3 | 2 | 3333 Third Lane
4 | 1 | 4444 Fourth Way
How do I get the most recent address (highest Address ID) for each employee? Ideally, I should be able to return:
EmpID | AddrID | Address
-------------------------------
1 | 3 | 1111 First Ave
2 | 4 | 2222 Second St
3 | 2 | 3333 Third Lane
4 | 1 | 4444 Fourth Way
So far I have either returned too many results (ie, every Employee, every AddrID 1, and every Address associated with the two), or too few results (ie, every Employee with an AddrID 4 - just Employee 2).
I have tried using Distinct, Group By, Order By, Having, and Self-Joins to no avail.
What am I missing?
You can use a subquery that gets the MAX() addrid for each empid:
select t1.empid,
t1.addrid,
t1.address
from table1 t1
inner join
(
select max(addrid) addrid, empid
from table1
group by empid
) t2
on t1.empid = t2.empid
and t1.addrid = t2.addrid
See SQL Fiddle With Demo
The inner query will return the max addrid and the empid then you join your table to that result on those two values this will limit the records that get returned.
The following should work:
SELECT *
FROM (SELECT empid,
Max(addrid) AS AddrID
FROM t1
GROUP BY empid) a
JOIN t1 b
ON b.empid = a.empid
AND b.addrid = a.addrid
See it in action
I would probably organize the table differently, but you could do something with a sub-join
select * from address_history
join
(select EmpID, max(AddrID) max_address from Address_History group by empId) as latest_addresses
on address_history.empid = latest_addresses
and address_history.addrId = latest_addresses.max_address
Related
Here's the situation:
So, in my database, a person is "responsible" for job X and "linked" to job Y. What I want is a query that returns: name of person, his ID and he number of jobs it's linked/responsible. So far I got this:
select id_job, count(id_job) number_jobs
from
(
select responsible.id
from responsible
union all
select linked.id
from linked
GROUP BY id
) id_job
GROUP BY id_job
And it returns a table with id in the first column and number of occurrences in the second. Now, what I can't do is associate the name of person to the table. When i put that in the "select" from beginning it gives me all the possible combinations... How can I solve this? Thanks in advance!
Example data and desirable output:
| Person |
id | name
1 | John
2 | Francis
3 | Chuck
4 | Anthony
| Responsible |
process_no | id
100 | 2
200 | 2
300 | 1
400 | 4
| Linked |
process_no | id
101 | 4
201 | 1
301 | 1
401 | 2
OUTPUT:
| OUTPUT |
id | name | number_jobs
1 | John | 3
2 | Francis | 3
3 | Chuck | 0
4 | Anthony | 2
Try this way
select prs.id, prs.name, count(*) from Person prs
join(select process_no, id
from Responsible res
Union all
select process_no, id
from Linked lin ) a on a.id=prs.id
group by prs.id, prs.name
I would recommend aggregating each of the tables by the person and then joining the results back to the person table:
select p.*, coalesce(r.cnt, 0) + coalesce(l.cnt, 0) as numjobs
from person p left join
(select id, count(*) as cnt
from responsible
group by id
) r
on r.id = p.id left join
(select id, count(*) as cnt
from linked
group by id
) l
on l.id = p.id;
select id, name, count(process_no) FROM (
select pr.id, pr.name, res.process_no from Person pr
LEFT JOIN Responsible res on pr.id = res.id
UNION
select pr.id, pr.name, lin.process_no from Person pr
LEFT JOIN Linked lin on pr.id = lin.id) src
group by id, name
order by id
Query ain't tested, give it a shot, but this is the way you want to go
I am trying to sum a few Decode statements and column names, but am having difficulties.
currently it is showing as
rank | name | points
----------------------
0 | john | 0
0 | john | 40
1 | john | 30
2 | tom | 22
0 | tom | 0
I expect to have this result:
rank | name | points
----------------------
1 | john | 70
2 | tom | 22
Query:
Select Rank, Name, Code, Points
From
(select
decode(Table.name, 'condition1', Table.value) As Points,
decode(Table.name, 'Condition2', Table.value) As Rank,
Employee.name as Name,
Employee.GA1 as Code
from Table
inner Join Employee
on Empolyee.positionseq = name.positionseq
where Table.name IN ('Condition1', 'Condition2')
);
Select MAX(Rank), Name, Code, SUM(Points)
From
(select
decode(Table.name, 'condition1', Table.value) As Points
decode(Table.name, 'Condition2', Table.value) As Rank
,Employee.name as Name
,Employee.GA1 as Code
from Table
inner Join Employee
on Employee.positionseq = name.positionseq
where Table.name IN( 'Condition1', 'Condition2'))
GROUP BY Employee.id;
I added the SUM, MAX (for rank) and GROUP BY statements. Also corrected some misspellings (Empolyee)
I may be understanding your question incorrectly, however, it seems like you are trying to do the following (omitting inner join for simplicity):
Select MAX(rank), name, SUM(points)
FROM UserRanks
GROUP BY name
Based on your data set above, you should get the following results:
rank name points
1 john 70
2 tom 22
I am having trouble with putting together INNER JOIN and COUNT in the same query.
Tables are:
TABLE STREETS
ID | STREET_NAME
------------------------
1 | Elm street
2 | Some other street
3 | Unknown street
4 | Killer street
5 | Dead-end street
TABLE ACCIDENTS_STREETS
STREET_ID | ACCIDENT_ID
-----------------------
2 | 4
2 | 7
2 | 2
2 | 1
5 | 3
I would like to get the street name where most accidents have occured.
This is for COUNT:
SELECT TOP 1 COUNT(STREET_ID) AS dangerous_street FROM ACCIDENTS_STREETS GROUP BY STREET_ID ORDER BY dangerous_street DESC
How to add INNER JOIN there to get only the name of the street?
Any advice is appreciated!
The Following should work
SELECT TOP 1 S.STREET_NAME,COUNT(a.*) AS dangerous_street
FROM ACCIDENTS_STREETS A
inner Join STREET S on S.ID = A.STREET_ID
GROUP BY S.STREET_NAME ORDER BY dangerous_street DESC
try this...
After joining the streets table, you would have to use an aggregation function to get the name in the resultset
SELECT
TOP 1 COUNT(STREET_ID) AS dangerous_street
, min( STREET_NAME) dangerous_STREET_NAME
FROM ACCIDENTS_STREETS acc
inner join STREETS str
on acc.STREET_ID=str.id
GROUP BY STREET_ID
ORDER BY dangerous_street DESC
I have a table of user data in my SQL Server database and I am attempting to summarize the data. Basically, I need some min, max, and sum values and to group by some columns
Here is a sample table:
Member ID | Name | DateJoined | DateQuit | PointsEarned | Address
00001 | Leyth | 1/1/2013 | 9/30/2013 | 57 | 123 FirstAddress Way
00002 | James | 2/1/2013 | 7/21/2013 | 34 | 4 street road
00001 | Leyth | 2/1/2013 | 10/15/2013| 32 | 456 LastAddress Way
00003 | Eric | 2/23/2013 | 4/14/2013 | 15 | 5 street road
I'd like the summarized table to show the results like this:
Member ID | Name | DateJoined | DateQuit | PointsEarned | Address
00001 | Leyth | 1/1/2013 | 10/15/2013 | 89 | 123 FirstAddress Way
00002 | James | 2/1/2013 | 7/21/2013 | 34 | 4 street road
00003 | Eric | 2/23/2013 | 4/14/2013 | 15 | 5 street road
Here is my query so far:
Select MemberID, Name, Min(DateJoined), Max(DateQuit), SUM(PointsEarned), Min(Address)
From Table
Group By MemberID
The Min(Address) works this time, it retrieves the address that corresponds to the earliest DateJoined. However, if we swapped the two addresses in the original table, we would retrieve "123 FirstAddress Way" which would not correspond to the 1/1/2013 date joined.
For almost everything you can use a simple groupby, but as you need "the same address than the row where the minimum datejoined is" is a little bit tricker and you can solve it in several ways, one is a subquery searching the address each time
SELECT
X.*,
(select Address
from #tmp t2
where t2.MemberID = X.memberID and
t2.DateJoined = (select MIN(DateJoined)
from #tmp t3
where t3.memberID = X.MemberID))
FROM
(select MemberID,
Name,
MIN(DateJoined) as DateJoined,
MAX(DateQuit) as DateQuit,
SUM(PointsEarned) as PointEarned
from #tmp t1
group by MemberID,Name
) AS X
`
Or other is a subquery with a Join
SELECT
X.*,
J.Address
FROM
(select
MemberID,
Name,
MIN(DateJoined) as DateJoined,
MAX(DateQuit) as DateQuit,
SUM(PointsEarned) as PointEarned
from #tmp t1
group by MemberID,Name
) AS X
JOIN #tmp J ON J.MemberID = X.MemberID AND J.DateJoined = X.DateJoined
You could rank your rows according to the date, and select the minimal one:
SELECT t.member_id,
name,
date_joined,
date_quit,
points_earned
address AS address
FROM (SELECT member_id
name,
MIN (date_joined) AS date_joined,
MAX (date_quit) AS date_quit,
SUM (points_earned) AS points_earned,
FROM my_table
GROUP BY member_id, name) t
JOIN (SELECT member_id,
address,
RANK() OVER (PARTITION BY member_id ORDER BY date_joined) AS rk
FROM my_table) addr ON addr.member_id = t.member_id AND rk = 1
SELECT DISTINCT st.memberid, st.name, m1.datejoined, m2.datequit, SUM(st.pointsearned), m1.Address
from SAMPLEtable st
LEFT JOIN ( SELECT memberid
, name
, MIN(datejoined)
, datequit
FROM sampletable
) m1 ON st.memberid = m1.memberid
LEFT JOIN ( SELECT memberid
, name
, datejoined
, MAX(datequit)
FROM sampletable
) m2 ON m1.memberid = m2.memberid
Say I have this table:
id | name
-------------
1 | john
2 | steve
3 | steve
4 | john
5 | steve
I only want the rows that are unique compared to the previous row, these:
id | name
-------------
1 | john
2 | steve
4 | john
5 | steve
I can partly achieve this by using this query:
SELECT *, (
SELECT `name` FROM demotable WHERE id=t.id-1
) AS prevName FROM demotable AS t GROUP BY prevName ORDER BY id ASC
But when I am using a query with multiple UNIONs and stuff, this gets way to complicated. Is there an easy way to do this (like GROUP BY, but than more specific)?
This should work, but I don't know if it's simpler :
select demotable.*
from demotable
left join demotable as prev on prev.id = demotable.id - 1
where demotable.name != prev.name