I am trying to pull the memberinstance from a table based on the max DateEnd. If it is Null I want to pull that as it would be still ongoing. I am using sql server.
select memberinstanceid
from table
group by memberid
having MAX(ISNULL(date_end, '2099-12-31'))
This query above doesnt work for me. I have tried different ones and have gotten it to return the separate instances, but not just the one with the max date.
Below is what my table looks like.
MemberID MemberInstanceID DateStart DateEnd
2 abc12 2013-01-01 2013-12-31
4 abc21 2010-01-01 2013-12-31
2 abc10 2015-01-01 NULL
4 abc19 2014-01-01 2014-10-31
I would expect my results to look like this
MemberInstanceID
abc10
abc19
I have been trying to figure out how to do this but have not had much luck. Any help would be much appreciated. Thanks
I think you need something like the following:
select MemberID, MemberInstanceID
from table t
where (
-- DateEnd is null...
DateEnd is null
or (
-- ...or pick the latest DateEnd for this member...
DateEnd = (
select max(DateEnd)
from table
where MemberID = t.MemberID
)
-- ... and check there's not a NULL entry for DateEnd for this member
and not exists (
select 1
from table
where MemberID = t.MemberID
and DateEnd is null
)
)
)
The problem with this approach would be if there are multiple rows that match for each member, i.e. multiple NULL rows with the same MemberID, or multiple rows with the same DateEnd for the same MemberID.
SELECT TOP 1 memberinstanceid
from table
ORDER BY (CASE WHEN [DateEnd] IS NULL THEN 1 ELSE 0 END) DESC,
[DateEnd] DESC
The ORDER BY is essentially creating a "column" to sort the NULL values to the top, then doing a secondary sort on the dates that are not null.
You have a good start but you don't need to perform any explicit grouping. What you want is the row where the EndDate is null or is the largest value (latest date) of all the records with the same MemberID. You also realized that the Max couldn't return the latest non-null date because the null, if one exists, must be the latest date.
select m.*
from Members m
where m.DateEnd is null
or m.DateEnd =(
select Max( IsNull( DateEnd, '9999-12-31' ))
from Members
where MemberID = m.MemberID );
Related
I do not understand why this code isn't working. I have a join which needs a different join condition depending on the result of a subselect.
When the term date is null, I want this to come after the and operator: and vs.term_date is null
When the term date is not null, I want the subquery below to come after the and operator. I need to join on the max effective date: vs.eff_date = (subquery)
I realize this code is messy, but I have to aggregate with a subselect since there are multiple rows coming back and I only want one. (but open to other solutions)
select *
From loc
inner join VendorSite vs
on loc.Record_Number = vs.SITE_NO
and --conditional join
case
when
(
case
when --if term date is null i want this after "and"
(select top 1 TERM_DATE
from VendorSite vs2
where vs2.SITE_NO = vs.SITE_NO
order by TERM_DATE asc) is null
then 1
else 0
end
) = 1
then vs.term_date is null
else --when term_date isn't null use max eff date
vs.eff_date =
(select max(eff_date)
from VendorSite vs2
where vs2.SITE_NO = loc.Record_Number)
end
Example: From the below dataset, I would only want to see the row where term_date is null come back.
site_no eff_date term_date
13588 2007-01-01 00:00:00.000 NULL
13588 2007-03-01 00:00:00.000 2007-11-09 00:00:00.000
In SQL SERVER 2008
Relation : Employee
empid clock-in clock-out date Cmpid
1 10 11 17-06-2015 001
1 11 12 17-06-2015 NULL
1 12 1 NULL 001
2 10 11 NULL 002
2 11 12 NULL 002
I need to populate table temp :
insert into temp
select distinct empid,date from employee
This gives all
3 records since they are distinct but what
I need is
empid date CMPID
1 17-06-2015 001
2 NULL 002
Depending on the size and scope of your table, it might just be more prudent to add
WHERE columnName is not null AND columnName2 is not null to the end of your query.
Null is different from other date value. If you wont exclude null record you have to add a and condition like table.filed is not null.
It sounds like what you want is a result table containing a row or tuple (relational databases don't have records) for every employee with a date column showing the date on which the worked or null if they didn't work. Right?
Something like this should do you:
select e.employee_id
from ( select distinct
empid
from employee
) master
left join employee detail on detail.empid = master.empid
and detail.date is not null
The master virtual table gives you the set of destinct employees; the detail gives you employees with non-null dates on which they worked. The left join gives you everything from master with any matches from detail blended in.
Rows in master with no matching rows in details, are returned once with the contributing columns from detail set to null. Rows in master with matching rows in detailare repeated once for each such match, with the detail columns reflecting the matching row's values.
This will give you the lowest date or null for each empid
SELECT empid,
MIN(date) date,
MIN(cmpid) cmpid
FROM employee
GROUP BY empid
try this
select distinct empid,date from employee where date is not null
I have a table with 3 fields like this sample table Tbl1
Person Cost FromDate
1 10 2009-1-1
1 20 2010-1-1
2 10 2009-1-1
I want to query it and get back the 3 fields and a generated field called ToDate that defaults to 2099-1-1 unless there is an actual ToDate implied from another entry for the person in the table.
select Person,Cost,FromDate,ToDate From Tbl1
Person Cost FromDate ToDate
1 10 2009-1-1 2010-1-1
1 20 2010-1-1 2099-1-1
2 10 2009-1-1 2099-1-1
You can select the minimum date from all dates that are after the record's date. If there is none you get NULL. With COALESCE you change NULL into the default date:
select
Person,
Cost,
FromDate,
coalesce((select min(FromDate) from Tbl1 later where later.FromDate > Tbl1.FromDate), '2099-01-01') as ToDate
From Tbl1
order by Person, FromDate;
Although Thorsten's answer is perfectly fine, it would be more efficient to use window-functions to match the derived end-dates.
;WITH nbrdTbl
AS ( SELECT Person, Cost, FromDate, row_nr = ROW_NUMBER() OVER (PARTITION BY Person ORDER BY FromDate ASC)
FROM Tbl1)
SELECT t.Person, t.Cost, t.FromDate, derived_end_date = COALESCE(nxt.FromDate, '9991231')
FROM nbrdTbl t
LEFT OUTER JOIN nbrdTbl nxt
ON nxt.Person = t.Person
AND nxt.row_nr = t.row_nr + 1
ORDER BY t.Person, t.FromDate
Doing a test on a 2000-records table it's about 3 times as efficient according to the Execution plan (78% vs 22%).
I have the following table:
row_num customer_status effective_from_datetime
------- ------------------ -----------------------
1 Active 2011-01-01
2 Active 2011-01-02
3 Active 2011-01-03
4 Suspended 2011-01-04
5 Suspended 2011-01-05
6 Active 2011-01-06
And am trying to achieve the following result whereby consecutive rows with the same status are merged into one row with an effective from and to date range:
customer_status effective_from_datetime effective_to_datetime
--------------- ----------------------- ---------------------
Active 2011-01-01 2011-01-04
Suspended 2011-01-04 2011-01-06
Active 2011-01-06 NULL
I can get a recursive CTE to output the correct effective_to_datetime based on the next row, but am having trouble merging the ranges.
Code to generate sample data:
CREATE TABLE #temp
(
row_num INT IDENTITY(1,1),
customer_status VARCHAR(10),
effective_from_datetime DATE
)
INSERT INTO #temp
VALUES
('Active','2011-01-01')
,('Active','2011-01-02')
,('Active','2011-01-03')
,('Suspended','2011-01-04')
,('Suspended','2011-01-05')
,('Active','2011-01-06')
EDIT SQL updated as per comment.
WITH
group_assigned_data AS
(
SELECT
ROW_NUMBER() OVER (PARTITION BY customer_status ORDER BY effective_from_date) AS status_sequence_id,
ROW_NUMBER() OVER ( ORDER BY effective_from_date) AS sequence_id,
customer_status,
effective_from_date
FROM
your_table
)
,
grouped_data AS
(
SELECT
customer_status,
MIN(effective_from_date) AS min_effective_from_date,
MAX(effective_from_date) AS max_effective_from_date
FROM
group_assigned_data
GROUP BY
customer_status,
sequence_id - status_sequence_id
)
SELECT
[current].customer_status,
[current].min_effective_from_date AS effective_from,
[next].min_effective_from_date AS effective_to
FROM
grouped_data AS [current]
LEFT JOIN
grouped_data AS [next]
ON [current].max_effective_from_date = [next].min_effective_from_date + 1
ORDER BY
[current].min_effective_from_date
This isn't recursive, but that's possibly a good thing.
It doesn't deal with gaps in your data. To deal with that you could create a calendar table, with every relevant date, and join on that to fill missing dates with 'unknown' status, and then run the query against that. (Infact you cate do it it a CTE that is used by the CTE above).
At present...
- If row 2 was missing, it would not change the result
- If row 3 was missing, the end_date of the first row would change
Different behaviour can be determined by preparing your data, or other methods. We'd need to know the business logic you need though.
If any one date can have multiple status entries, you need to define what logic you want it to follow. At present the behaviour is undefined, but you could correct that as simply as adding customer_status to the ORDER BY portions of ROW_NUMBER().
I am trying to solve this query. I have the following data:
Input
Date Id Value
25-May-2011 1 10
26-May-2011 1 10
26-May-2011 2 10
27-May-2011 1 20
27-May-2011 2 20
28-May-2011 1 10
I need to query and output as:
Output
FromDate ToDate Id Value
25-May-2011 26-May-2011 1 10
26-May-2011 26-May-2011 2 10
27-May-2011 27-May-2011 1 20
28-May-2011 28-May-2011 1 10
I tried this sql but I'm not getting the correct result:
SELECT START_DATE, END_DATE, A.KEY, B.VALUE FROM
(
SELECT MIN(DATE) START_DATE, KEY, VALUE
FROM
KEY_VALUE
GROUP
BY KEY,VALUE
) A INNER JOIN
(
SELECT MAX(DATE) END_DATE, KEY, VALUE
FROM
KEY_VALUE
GROUP
BY KEY, VALUE
) B ON A.KEY = B.KEY AND A.VALUE = B.VALUE;
I think that you are trying too hard. Should be more like this:
SELECT MIN(START_DATE) AS FromDate, MAX(END_DATE) AS ToDate, KEY, VALUE
FROM KEY_VALUE
GROUP BY KEY, VALUE
This query appears to produce the correct results, though it pointed out that you missed a line in your example output '27-May-2011 ... 27-May-2011 ... 2 ... 20'.
select id, [value], date as fromdate, (
select top 1 date
from key_value kv2
where id = kv.id
and [value] = kv.[value]
and date >= kv.date
and datediff(d, kv.date, date) = (
select count(*)
from key_value
where id = kv.id
and [value] = kv.[value]
and date > kv.date
and date <= kv2.date
)
order by date desc
) as todate
from key_value kv
where not exists (
select *
from key_value
where id = kv.id
and [value] = kv.[value]
and date = dateadd(d, -1, kv.[date])
)
First it finds the min date records with the where clause, looking for records that do not have another record on the day before. Then the todate subquery gets the greatest date record by finding the number of days between it and min date then finding the number of records between the two and making sure they match. This of course assumes that the records in the table are distinct.
However if you are processing a massive table your best option may be to sort the records by key, id, date and then use a cursor to programmatically find the min and max dates as you loop over and look for values to change, then push them into a new table whether real or temp along with any other calculations you might need to do on other fields along the way.