I have table that looks like the following
I have to select every second record per PatientID that would give the following result (my last query returns this result)
I then have to select the record with the oldest date which would be the following (this is the end result I want)
What I have done so far: I have a CTE that gets all the data I need
WITH cte
AS
(
SELECT visit.PatientTreatmentVisitID, mat.PatientMatchID,pat.PatientID,visit.RegimenDate AS VisitDate,
ROW_NUMBER() OVER(PARTITION BY mat.PatientMatchID, pat.PatientID ORDER BY visit.VisitDate ASC) AS RowNumber
FROM tblPatient pat INNER JOIN tblPatientMatch mat ON mat.PatientID = pat.PatientID
LEFT JOIN tblPatientTreatmentVisit visit ON visit.PatientID = pat.PatientID
)
I then write a query against the CTE but so far I can only return the second row for each patientID
SELECT *
FROM
(
SELECT PatientTreatmentVisitID,PatientMatchID,PatientID, VisitDate, RowNumber FROM cte
) as X
WHERE RowNumber = 2
How do I return the record with the oldest date only? Is there perhaps a MIN() function that I could be including somewhere?
If I follow you correctly, you can just order your existing resultset and retain the top row only.
In standard SQL, you would write this using a FETCH clause:
SELECT *
FROM (
SELECT
visit.PatientTreatmentVisitID,
mat.PatientMatchID,
pat.PatientID,
visit.RegimenDate AS VisitDate,
ROW_NUMBER() OVER(PARTITION BY mat.PatientMatchID, pat.PatientID ORDER BY visit.VisitDate ASC) AS rn
FROM tblPatient pat
INNER JOIN tblPatientMatch mat ON mat.PatientID = pat.PatientID
LEFT JOIN tblPatientTreatmentVisit visit ON visit.PatientID = pat.PatientID
) t
WHERE rn = 2
ORDER BY VisitDate
OFFSET 0 ROWS FETCH FIRST 1 ROW ONLY
This syntax is supported in Postgres, Oracle, SQL Server (and possibly other databases).
If you need to get oldest date from all selected dates (every second row for each patient ID) then you can try window function Min:
SELECT * FROM
(
SELECT *, MIN(VisitDate) OVER (Order By VisitDate) MinDate
FROM
(
SELECT PatientTreatmentVisitID,PatientMatchID,PatientID, VisitDate,
RowNumber FROM cte
) as X
WHERE RowNumber = 2
) Y
WHERE VisitDate=MinDate
Or you can use SELECT TOP statement. The SELECT TOP clause allows you to limit the number of rows returned in a query result set:
SELECT TOP 1 PatientTreatmentVisitID,PatientMatchID,PatientID, VisitDate FROM
(
SELECT *
FROM
(
SELECT PatientTreatmentVisitID,PatientMatchID,PatientID, VisitDate,
RowNumber FROM cte
) as X
WHERE RowNumber = 2
) Y
ORDER BY VisitDate
For simplicity add order desc on date column and use TOP to get the first row only
SELECT TOP 1 *
FROM
(
SELECT PatientTreatmentVisitID,PatientMatchID,PatientID, VisitDate, RowNumber FROM cte
) as X
WHERE RowNumber = 2
order by VisitDate desc
Related
I have a table with Name and Date columns. I want to get the earliest date when the current name appeared. For example:
Name
Date
X
30-Jan-2021
X
29-Jan-2021
X
28-Jan-2021
Y
27-Jan-2021
Y
26-Jan-2021
Y
25-Jan-2021
Y
24-Jan-2021
X
23-Jan-2021
X
22-Jan-2021
Now when I try to get the earliest date when current name (X) started to appear, I want 28-Jan, but the sql query would give 22-Jan-2021 because that's when X appeared originally for the first time.
Update: This was the query I was using:
Select min(Date) from myTable where Name='X'
I am using older SQL Server 2008 (in the process of upgrading), so do not have access to LEAD/LAG functions.
The solutions suggested below do work as intended. Thanks.
This is a type of gaps-and-islands problem.
There are many solutions. Here is one that is optimized for your case
Use LEAD/LAG to identify the first row in each grouping
Filter to only those rows
Number them rows and take the first one
WITH StartPoints AS (
SELECT *,
IsStart = CASE WHEN Name <> LEAD(Name, 1, '') OVER (ORDER BY Date DESC) THEN 1 END
FROM YourTable
),
Numbered AS (
SELECT *,
rn = ROW_NUMBER() OVER (PARTITION BY Name ORDER BY Date DESC)
FROM StartPoints
WHERE IsStart = 1 AND Name = 'X'
)
SELECT
Name, Date
FROM Numbered
WHERE rn = 1;
db<>fiddle
For SQL Server 2008 or earlier (which I strongly suggest you upgrade from), you can use a self-join with row-numbering to simulate LEAD/LAG
WITH RowNumbered AS (
SELECT *,
AllRn = ROW_NUMBER() OVER (ORDER BY Date ASC)
FROM YourTable
),
StartPoints AS (
SELECT r1.*,
IsStart = CASE WHEN r1.Name <> ISNULL(r2.Name, '') THEN 1 END
FROM RowNumbered r1
LEFT JOIN RowNumbered r2 ON r2.AllRn = r1.AllRn - 1
),
Numbered AS (
SELECT *,
rn = ROW_NUMBER() OVER (PARTITION BY Name ORDER BY Date DESC)
FROM StartPoints
WHERE IsStart = 1
)
SELECT
Name, Date
FROM Numbered
WHERE rn = 1;
This is a gaps and island problem. Based on the sample data, this will work:
WITH Groups AS(
SELECT YT.[Name],
YT.[Date],
ROW_NUMBER() OVER (ORDER BY YT.Date DESC) -
ROW_NUMBER() OVER (PARTITION BY YT.[Name] ORDER BY Date DESC) AS Grp
FROM dbo.YourTable YT),
FirstGroup AS(
SELECT TOP (1) WITH TIES
G.[Name],
G.[Date]
FROM Groups G
WHERE [Name] = 'X'
ORDER BY Grp ASC)
SELECT MIN(FG.[Date]) AS Mi
db<>fiddle
If i did understand, you want to know when the X disappeared and reappeared again. in that case you can search for gaps in dates by group.
this and example how to detect that
SELECT name
,DATE
FROM (
SELECT *
,DATEDIFF(day, lead(DATE) OVER (
PARTITION BY name ORDER BY DATE DESC
), DATE) DIF
FROM YourTable
) a
WHERE DIF > 1
I have following table:
I need to filter out the rows for which start date is latest corresponding to its order id .With reference to given table row no 2 and 3 should be the output.
As row 1 and row 2 has same order id and order date but start date is later than first row. And same goes with row number 3 and 4 hence I need to take out row no 3 . I am trying to write the query in SQL server. Any help is appreciated.Please let me know if you need more details.Apologies for poor English
You can do this easily with a ROW_NUMBER() windowed function:
;With Cte As
(
Select *,
Row_Number() Over (Partition By OrderId Order By StartDate Desc) RN
From YourTable
)
Select *
From Cte
Where RN = 1
But I question the StartDate datatype. It looks like these are being stored as VARCHAR. If that is the case, you need to CONVERT the value to a DATETIME:
;With Cte As
(
Select *,
Row_Number() Over (Partition By OrderId
Order By Convert(DateTime, StartDate) Desc) RN
From YourTable
)
Select *
From Cte
Where RN = 1
Another way using a derived table.
select
t.*
from
YourTable t
inner join
(select OrderId, max(StartDate) dt
from YourTable
group by OrderId) t2 on t2.dt = t.StartDate and t2.OrderId = t.OrderId
I think it's easier to show you an image:
So, for each fld_call_id, go to the next value, if it's identical. When we get to the last value, I need the value in column fld_menu_id.
Or, to put it in another way, eliminate fld_call_id duplicates and save only the last one.
You can use ROW_NUMBER:
WITH CTE AS(
SELECT RN = ROW_NUMBER() OVER (PARTITION BY fld_call_id ORDER BY fld_id DESC),
fld_menu_id
FROM dbo.TableName
)
SELECT fld_menu_id FROM CTE WHERE RN = 1
You can create a Rank column and only select that row, something along the lines of the following:
;WITH cte AS
(
SELECT
*
,RANK() OVER (PARTITION BY fld_call_id ORDER BY fld_id DESC) Rnk
FROM YourTable
)
SELECT
*
FROM cte
WHERE Rnk=1
So you GROUP BY fld_call_id and ORDER BY fld_id in descending order so that the last value comes first. These are the rows where Rnk=1.
Edit after comments of OP.
SELECT Table.*
FROM Table
INNER JOIN
(
SELECT MAX(fldMenuID) AS fldMenuID,
fldCallID
FROM Table
GROUP BY fldCallID
) maxValues
ON (maxValues.fldMenuID = Table.fldMenuID
AND maxValues.fldCallID= Table.fldCallID)
Hope This works
SELECT A.*
FROM table A
JOIN (SELECT fld_id,
ROW_NUMBER() OVER (PARTITION BY Fld_call_id ORDER BY fld_id DESC) [Row]
FROM table) LU ON A.fld_id = LU.fld_id
WHERE LU.[Row] = 1
My query is as follows
BEGIN
WITH MyCTE
AS (
SELECT T.MusicAlbumTitle
,D.musicTitle
,D.mVideoID
,D.musicFileName
,T.ReleaseDate AS ReleasedDate
,D.MusicLength
,D.musicSinger
,D.MusicVideoID
,D.ExternalLink
,D.CoverImg
,ROW_NUMBER() OVER (
PARTITION BY D.MusicVideoID ORDER BY D.mVideoID
) AS row_num
FROM dbo.Music_Video T
JOIN dbo.Music_Video_Details D ON T.MusicVideoID = D.MusicVideoID
WHERE T.PortalID = #PortalID
AND T.CultureCode = #CultureCode
AND T.ComingSoon <> 1
GROUP BY T.MusicAlbumTitle
,D.musicTitle
,D.mVideoID
,T.ReleaseDate
,D.musicFileName
,D.MusicLength
,D.musicSinger
,D.MusicVideoID
,D.ExternalLink
,D.CoverImg
)
SELECT a.mVideoID
,a.MusicVideoID
,a.musicFileName
,a.MusicAlbumTitle
,a.ReleasedDate
,a.row_num
,a.CoverImg
,a.ExternalLink
,a.musicTitle
,a.MusicLength
FROM MyCTE a
WHERE row_num = 1
ORDER BY MusicVideoID DESC
END
I need to achieve total row count from last select statement.
which mean total row count that is being selected.
or any idea that might be use in this condition
How can i do this ..
Please add COUNT(*) OVER() in your select, which returns total rows selected as a new column.
Ex:
SELECT
*,
COUNT(*) OVER() AS [Total_Rows]
FROM YourTable
Just to be clear, you need to add the count to the CTE, not the outer query. The outer select is returning only one row, so the count would always be one.
The CTE should start:
WITH MyCTE
AS (
SELECT T.MusicAlbumTitle
,D.musicTitle
,D.mVideoID
,D.musicFileName
,T.ReleaseDate AS ReleasedDate
,D.MusicLength
,D.musicSinger
,D.MusicVideoID
,D.ExternalLink
,D.CoverImg
,ROW_NUMBER() OVER (
PARTITION BY D.MusicVideoID ORDER BY D.mVideoID
) AS row_num,
COUNT(*) over () as total_count
I need a SQL query that returns the top 2 Plans by PlanDate per ClientID. This is all on one table where PlanID is the PrimaryID, ClientID is a foreignID.
This is what I have so far -->
SELECT *
FROM [dbo].[tblPlan]
WHERE [PlanID] IN (SELECT TOP (2) PlanID FROM [dbo].[tblPlan] ORDER BY [PlanDate] DESC)
This, obviously, only returns 2 records where I actually need up to 2 records per ClientID.
This can be done using ROW_NUMBER:
SELECT PlanId, ClientId, PlanDate FROM (
SELECT ROW_NUMBER() OVER (PARTITION BY ClientId ORDER BY PlanDate DESC) rn, *
FROM [dbo].[tblPlan]
) AS T1
WHERE rn <=2
Add any other columns you need to the select to get those too.
Edit, Dec 2011. Corrected CROSS APPLY solution
Try both to see what is best
SELECT *
FROM
( -- distinct ClientID values
SELECT DISTINCT ClientID
FROM [dbo].[tblPlan]
) P1
CROSS APPLY
( -- top 2 per ClientID
SELECT TOP (2) P2.PlanID
FROM [dbo].[tblPlan] P2
WHERE P1.ClientID = P2.ClientID
ORDER BY P2.[PlanDate] DESC
) foo
Or
;WITH cTE AS (
SELECT
*,
ROW_NUMBER () OVER (PARTITION BY clientid ORDER BY [PlanDate] DESC) AS Ranking
FROM
[dbo].[tblPlan]
)
SELECT * FROM cTE WHERE Ranking <= 2