Select from results of query? - sql

I have a query like this:
SELECT Weighings.Member, MIN(Sessions.DateTime) AS FirstDate, MAX(Sessions.DateTime) AS LastDate
FROM Weighings AS Weighings INNER JOIN
Sessions ON Sessions.SessionGUID = Weighings.Session
WHERE (Sessions.DateTime >= '01/01/2011')
GROUP BY Weighings.Member
ORDER BY Weighings.Member
It returns this:
Member | FirstDate | LastDate
Blah | 01/01/11 | 06/07/11
Blah2 | 02/03/11 | 05/07/11
I need to get the value of a cell Weight_kg in table Weighings for the returned values FirstDate and LastDate to give results like so:
Member | FirstWeight | LastWeight
Blah | 150Kg | 60KG
Blah2 | 70Kg | 72KG
I have tried all combinations of things but just can't work it out, any ideas?
EDIT
Tables:
Sessions
______________________
SessionGUID | DateTime
----------------------
12432524325 | 01/01/11
12432524324 | 01/08/11
12432524323 | 01/15/11
34257473563 | 03/05/11
43634574545 | 06/07/11
Weighings
_____________________________________
Member | Session | Weight_kg
-------------------------------------
vffd8fdg87f | 12432524325 | 150
vffd8fdg87f | 12432524324 | 120
vffd8fdg87f | 12432524323 | 110
ddffv89sdv8 | 34257473563 | 124
32878vfdsv8 | 43634574545 | 75

;with C as
(
select W.Member,
W.Weight_kg,
row_number() over(partition by W.Member order by S.datetime desc) as rnLast,
row_number() over(partition by W.Member order by S.datetime asc) as rnFirst
from Weighings as W
inner join Sessions as S
on S.sessionguid = W.Session and
S.DateTime >= '20110101'
)
select CF.Member,
CF.Weight_kg as FirstWeight,
CL.Weight_kg as LastWeigth
from C as CF
inner join C as CL
on CF.Member = CL.Member
where CF.rnFirst = 1 and
CL.rnLast = 1
Try here: https://data.stackexchange.com/stackoverflow/q/118518/

You can use the RANK..OVER stmt (works only on SQL 2k5+)
select fw.Member, st.Weight, en.Weight
from
(
select Member, Weight, RANK() OVER(PARTITION BY Member ORDER BY Weight) rnk
from Weighings
) st
inner join
(
select Member, Weight, RANK() OVER(PARTITION BY Member ORDER BY WeightDESC) rnk
from Weighings
) en on en.Member= st.Member and st.rnk = 1 and en.rnk = 1

You have two possibilities.
If you want to reuse the first SELECT more times, I'd suggest to sreate temporary table
CREATE TEMPORARY TABLE `tmpTable` AS SELECT /*the first select*/ ;
/*and then*/
SELECT * FROM `tmpTable` /*the second select from the first select*/
If you require the first select only once
SELECT first.*
FROM (SELECT /*the first select*/) AS first

Related

Select first rows where condition [duplicate]

Here's what I'm trying to do. Let's say I have this table t:
key_id | id | record_date | other_cols
1 | 18 | 2011-04-03 | x
2 | 18 | 2012-05-19 | y
3 | 18 | 2012-08-09 | z
4 | 19 | 2009-06-01 | a
5 | 19 | 2011-04-03 | b
6 | 19 | 2011-10-25 | c
7 | 19 | 2012-08-09 | d
For each id, I want to select the row containing the minimum record_date. So I'd get:
key_id | id | record_date | other_cols
1 | 18 | 2011-04-03 | x
4 | 19 | 2009-06-01 | a
The only solutions I've seen to this problem assume that all record_date entries are distinct, but that is not this case in my data. Using a subquery and an inner join with two conditions would give me duplicate rows for some ids, which I don't want:
key_id | id | record_date | other_cols
1 | 18 | 2011-04-03 | x
5 | 19 | 2011-04-03 | b
4 | 19 | 2009-06-01 | a
How about something like:
SELECT mt.*
FROM MyTable mt INNER JOIN
(
SELECT id, MIN(record_date) AS MinDate
FROM MyTable
GROUP BY id
) t ON mt.id = t.id AND mt.record_date = t.MinDate
This gets the minimum date per ID, and then gets the values based on those values. The only time you would have duplicates is if there are duplicate minimum record_dates for the same ID.
I could get to your expected result just by doing this in mysql:
SELECT id, min(record_date), other_cols
FROM mytable
GROUP BY id
Does this work for you?
To get the cheapest product in each category, you use the MIN() function in a correlated subquery as follows:
SELECT categoryid,
productid,
productName,
unitprice
FROM products a WHERE unitprice = (
SELECT MIN(unitprice)
FROM products b
WHERE b.categoryid = a.categoryid)
The outer query scans all rows in the products table and returns the products that have unit prices match with the lowest price in each category returned by the correlated subquery.
I would like to add to some of the other answers here, if you don't need the first item but say the second number for example you can use rownumber in a subquery and base your result set off of that.
SELECT * FROM
(
SELECT
ROW_NUM() OVER (PARTITION BY Id ORDER BY record_date, other_cols) as rownum,
*
FROM products P
) INNER
WHERE rownum = 2
This also allows you to order off multiple columns in the subquery which may help if two record_dates have identical values. You can also partition off of multiple columns if needed by delimiting them with a comma
This does it simply:
select t2.id,t2.record_date,t2.other_cols
from (select ROW_NUMBER() over(partition by id order by record_date)as rownum,id,record_date,other_cols from MyTable)t2
where t2.rownum = 1
If record_date has no duplicates within a group:
think of it as of filtering. Simpliy get (WHERE) one (MIN(record_date)) row from the current group:
SELECT * FROM t t1 WHERE record_date = (
select MIN(record_date)
from t t2 where t2.group_id = t1.group_id)
If there could be 2+ min record_date within a group:
filter out non-min rows (see above)
then (AND) pick only one from the 2+ min record_date rows, within the given group_id. E.g. pick the one with the min unique key:
AND key_id = (select MIN(key_id)
from t t3 where t3.record_date = t1.record_date
and t3.group_id = t1.group_id)
so
key_id | group_id | record_date | other_cols
1 | 18 | 2011-04-03 | x
4 | 19 | 2009-06-01 | a
8 | 19 | 2009-06-01 | e
will select key_ids: #1 and #4
SELECT p.* FROM tbl p
INNER JOIN(
SELECT t.id, MIN(record_date) AS MinDate
FROM tbl t
GROUP BY t.id
) t ON p.id = t.id AND p.record_date = t.MinDate
GROUP BY p.id
This code eliminates duplicate record_date in case there are same ids with same record_date.
If you want duplicates, remove the last line GROUP BY p.id.
This a old question, but this can useful for someone
In my case i can't using a sub query because i have a big query and i need using min() on my result, if i use sub query the db need reexecute my big query. i'm using Mysql
select t.*
from (select m.*, #g := 0
from MyTable m --here i have a big query
order by id, record_date) t
where (1 = case when #g = 0 or #g <> id then 1 else 0 end )
and (#g := id) IS NOT NULL
Basically I ordered the result and then put a variable in order to get only the first record in each group.
The below query takes the first date for each work order (in a table of showing all status changes):
SELECT
WORKORDERNUM,
MIN(DATE)
FROM
WORKORDERS
WHERE
DATE >= to_date('2015-01-01','YYYY-MM-DD')
GROUP BY
WORKORDERNUM
select
department,
min_salary,
(select s1.last_name from staff s1 where s1.salary=s3.min_salary ) lastname
from
(select department, min (salary) min_salary from staff s2 group by s2.department) s3

SQL Server - Select Distinct of two columns, where the distinct column selected has a maximum value based on two other columns

I have 2 tables - TC and T, with columns specified below. TC maps to T on column T_ID.
TC
----
T_ID,
TC_ID
T
-----
T_ID,
V_ID,
Datetime,
Count
My current result set is:
V_ID TC_ID Datetime Count
----|-----|------------|--------|
2 | 1 | 2013-09-26 | 450600 |
2 | 1 | 2013-12-09 | 14700 |
2 | 1 | 2014-01-22 | 15000 |
2 | 1 | 2014-01-22 | 15000 |
2 | 1 | 2014-01-22 | 7500 |
4 | 1 | 2014-01-22 | 1000 |
4 | 1 | 2013-12-05 | 0 |
4 | 2 | 2013-12-05 | 0 |
Using the following query:
select T.V_ID,
TC.TC_ID,
T.Datetime,
T.Count
from T
inner join TC
on TC.T_ID = T.T_ID
Result set I want:
V_ID TC_ID Datetime Count
----|-----|------------|--------|
2 | 1 | 2014-01-22 | 15000 |
4 | 1 | 2014-01-22 | 1000 |
4 | 2 | 2013-12-05 | 0 |
I want to write a query to select each distinct V_ID + TC_ID combination, but only with the maximum datetime, and for that datetime the maximum count. E.g. for the distinct combination of V_ID = 2 and TC_ID = 1, '2014-01-22' is the maximum datetime, and for that datetime, 15000 is the maximum count, so select this record for the new table. Any ideas? I don't know if this is too ambitious for a query and I should just handle the result set in code instead.
One method uses row_number():
select v_id, tc_id, datetime, count
from (select T.V_ID, TC.TC_ID, T.Datetime, T.Count,
row_number() over (partition by t.V_ID, tc.tc_id
order by datetime desc, count desc
) as seqnum
from t join
tc
on tc.t_id = t._id
) tt
where seqnum = 1;
The only issue is that some rows have the same maximum datetime value. SQL tables represent unordered sets, so there is no way to determine which is really the maximum -- unless the datetime really has a time component or another column specifies the ordering within a day.
It is possible to solve this using CTEs. First, extracting the data from your query. Second, get the maxdates. Third, get the highest count for each maxdate.:
;WITH Dataset AS
(
select T.V_ID,
TC.TC_ID,
T.[Datetime],
T.[Count]
from T
inner join TC
on TC.T_ID = T._ID
),
MaxDates AS
(
SELECT V_ID, TC_ID, MAX(t.[Datetime]) AS MaxDate
FROM Dataset t
GROUP BY t.V_ID, t.TC_ID
)
SELECT t.V_ID, t.TC_ID, t.[Datetime], MAX(t.[Count]) AS [Count]
FROM Dataset t
INNER JOIN MaxDates m ON t.V_ID = m.V_ID AND t.TC_ID = m.TC_ID AND m.MaxDate = t.[Datetime]
GROUP BY t.V_ID, t.TC_ID, t.[Datetime]
Just to keep it simple:
You need to group by T.V_ID,TC.TC_ID,
with selecting the max of date and then to get the maximum count, you must use a sub query as follows,
select T.V_ID,
TC.TC_ID,
max(T.Datetime) as Date_Time,
(select max(Count) from T as tb where v_ID = T.v_ID and DateTime = max(T.DateTime)) as Count
from T
inner join TC
on TC.T_ID = T._ID
group by T.V_ID,TC.TC_ID,

Selecting Top 1 for Every ID

I have the following table:
| ID | ExecOrd | date |
| 1 | 1.0 | 3/4/2014|
| 1 | 2.0 | 7/7/2014|
| 1 | 3.0 | 8/8/2014|
| 2 | 1.0 | 8/4/2013|
| 2 | 2.0 |12/2/2013|
| 2 | 3.0 | 1/3/2014|
| 2 | 4.0 | |
I need to get the date of the top ExecOrd per ID of about 8000 records, and so far I can only do it for one ID:
SELECT TOP 1 date
FROM TABLE
WHERE DATE IS NOT NULL and ID = '1'
ORDER BY ExecOrd DESC
A little help would be appreciated. I have been trying to find a similar question to mine with no success.
There are several ways of doing this. A generic approach is to join the table back to itself using max():
select t.date
from yourtable t
join (select max(execord) execord, id
from yourtable
group by id
) t2 on t.id = t2.id and t.execord = t2.execord
If you're using 2005+, I prefer to use row_number():
select date
from (
select row_number() over (partition by id order by execord desc) rn, date
from yourtable
) t
where rn = 1;
SQL Fiddle Demo
Note: they will give different results if ties exist.
;with cte as (
SELECT id,row_number() over(partition by ID order byExecOrd DESC) r
FROM TABLE WHERE DATE IS NOT NULL )
select id from
cte where r=1

SQL Server : select from duplicate columns where date newest

I have inherited a SQL Server table in the (abbreviated) form of (includes sample data set):
| SID | name | Invite_Date |
|-----|-------|-------------|
| 101 | foo | 2013-01-06 |
| 102 | bar | 2013-04-04 |
| 101 | fubar | 2013-03-06 |
I need to select all SID's and the Invite_date, but if there is a duplicate SID, then just get the latest entry (by date).
So the results from the above would look like:
101 | fubar | 2013-03-06
102 | bar | 2013-04-04
Any ideas please.
N.B the Invite_date column has been declared as a nvarchar, so to get it in a date format I am using CONVERT(DATE, Invite_date)
You can use a ranking function like ROW_NUMBER or DENSE_RANK in a CTE:
WITH CTE AS
(
SELECT SID, name, Invite_Date,
rn = Row_Number() OVER (PARTITION By SID
Order By Invite_Date DESC)
FROM dbo.TableName
)
SELECT SID, name, Invite_Date
FROM CTE
WHERE RN = 1
Demo
Use Row_Number if you want exactly one row per group and Dense_Rank if you want all last Invite_Date rows for each group in case of repeating max-Invite_Dates.
select t1.*
from your_table t1
inner join
(
select sid, max(CONVERT(DATE, Invite_date)) mdate
from your_table
group by sid
) t2 on t1.sid = t2.sid and CONVERT(DATE, t1.Invite_date) = t2.mdate
select
SID,name,MAX(Invite_date)
FROM
Table1
GROUP BY
SID
http://sqlfiddle.com/#!2/6b6f66/1

how to query range?

Raw Data
| ID | STATUS |
| 1 | A |
| 2 | A |
| 3 | B |
| 4 | B |
| 5 | B |
| 6 | A |
| 7 | A |
| 8 | A |
| 9 | C |
Result
| START | END |
| 1 | 2 |
| 6 | 8 |
Range of STATUS A
How to query ?
This should give you the correct ranges:
SELECT
STATUS,
MIN(ID),
max_id
FROM (
SELECT
t1.STATUS,
t1.ID,
COALESCE(MAX(t2.ID), t1.ID) max_id
FROM
yourtable t1 LEFT JOIN yourtable t2
ON t1.STATUS=t2.STATUS AND t1.ID<t2.ID
WHERE
NOT EXISTS (SELECT NULL
FROM yourtable t3
WHERE
t3.STATUS!=t1.STATUS
AND t3.ID>t1.ID AND t3.ID<t2.ID)
GROUP BY
t1.ID,
t1.STATUS
) s
WHERE
status = 'A'
GROUP BY
STATUS,
max_id
Please see fiddle here.
You are probably better off with a cursor-based solution or a client-side function.
However, if you were using Oracle - the following would work.
WITH LOWER_VALS AS
( -- All the Ids with no immediate predecessor
SELECT ROWNUM AS RN, STATUS, ID AS LOWER FROM
(
SELECT STATUS, ID
FROM RAWDATA RD1
WHERE RD1.ID -1 NOT IN
(SELECT ID FROM RAWDATA PRED_TABLE WHERE PRED_TABLE.STATUS = RD1.STATUS)
ORDER BY STATUS, ID
)
) ,
UPPER_VALS AS
( -- All the Ids with no immediate successor
SELECT ROWNUM AS RN, STATUS, ID AS UPPER FROM
(
SELECT STATUS, ID
FROM RAWDATA RD2
WHERE RD2.ID +1 NOT IN
(SELECT ID FROM RAWDATA SUCC_TABLE WHERE SUCC_TABLE.STATUS = RD2.STATUS)
ORDER BY STATUS, ID
)
)
SELECT
L.STATUS, L.LOWER, U.UPPER
FROM
LOWER_VALS L
JOIN UPPER_VALS U ON
U.RN = L.RN;
Results in the set
A 1 2
A 6 8
B 3 5
C 9 9
http://sqlfiddle.com/#!4/10184/2
There is not a lot to go on from what you put, but I think this might work. I am using T-SQL because I don't know what you are using?
SELECT
min(ID)
, max(ID)
FROM RawData
WHERE [Status] = 'A'