I want to store the top 2 results in 2 variables.
create table t(id int);
insert into t (id) values (1),(2),(3),(4);
declare #id1 int
declare #id2 int
select top 2 #id1 = first id,
#id2 = next id
from t
SQLFiddle
Can I do it in one query without using a loop?
declare #id1 int,#id2 int
;with cte as (
select top (2) id
from t
order by id
)
select #id1 = min(id), #id2 = max(id)
from cte
select #id1,#id2
Fiddle demo
with cte as (
select top 2 id, row_number() over(order by id) as rn
from t
order by id
)
select
#id1 = (select id from cte where rn = 1),
#id2 = (select id from cte where rn = 2)
or
with cte as (
select top 2 id, row_number() over(order by id) as rn
from t
order by id
)
select
#id1 = max(case when rn = 1 then id end),
#id2 = max(case when rn = 2 then id end)
from cte
sql fiddle demo
You can use LEAD() for SQL Server 2012.
SELECT TOP 1 #id1 = ID, #id2 = LEAD(ID) OVER (ORDER BY ID) FROM t
SQLFiddle Demo
With two SELECT it's easy...
DECLARE #id1 INT
DECLARE #id2 INT
SELECT TOP 1 #id1 = x.id
FROM (SELECT *, ROW_NUMBER() OVER (ORDER BY id) RN FROM t) x
WHERE x.RN = 1
SELECT TOP 1 #id2 = x.id
FROM (SELECT *, ROW_NUMBER() OVER (ORDER BY id) RN FROM t) x
WHERE x.RN = 2
SELECT #id1, #id2
With SQL 2012 you clearly could
SELECT #id1 = id
FROM t ORDER BY id OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY
SELECT #id2 = id
FROM t ORDER BY id OFFSET 1 ROWS FETCH NEXT 1 ROWS ONLY
Or evein in 2008 you could
; WITH Base AS (
SELECT *, ROW_NUMBER() OVER (ORDER BY id) RN FROM t
)
SELECT #id1 = b1.id, #id2 = b2.id
FROM Base b1, Base b2
WHERE b1.RN = 1 AND B2.RN = 2
declare #id1 int
declare #id2 int
declare #table table(id int,rownum int)
insert into #table
select top 2 id,row_number() over( order by id) as rn from t
select #id1=case rownum when 1 then id else #id1 end,
#id2=case rownum when 2 then id end from #table
select #id1,#id2
SQL FIDDLE
More easy way with 2 selects:
declare #id1 int
declare #id2 int
select top 1 #id1 = id from t
select top 2 #id2 = id from t
select #id1, #id2
SQL Fiddle
Related
Sample data:
create table #temp (id int, qty int, checkvalue int)
insert into #temp values (1,1,3)
insert into #temp values (2,2,3)
insert into #temp values (3,1,3)
insert into #temp values (4,1,3)
According to data above, I would like to show exact number of lines from top to bottom where sum(qty) = checkvalue. Note that checkvalue is same for all the records all the time. Regarding the sample data above, the desired output is:
Id Qty checkValue
1 1 3
2 2 3
Because 1+2=3 and no more data is needed to show. If checkvalue was 4, we would show the third record: Id:3 Qty:1 checkValue:4 as well.
This is the code I am handling this problem. The code is working very well.
declare #checkValue int = (select top 1 checkvalue from #temp);
declare #counter int = 0, #sumValue int = 0;
while #sumValue < #checkValue
begin
set #counter = #counter + 1;
set #sumValue = #sumValue + (
select t.qty from
(
SELECT * FROM (
SELECT
ROW_NUMBER() OVER (ORDER BY id ASC) AS rownumber,
id,qty,checkvalue
FROM #temp
) AS foo
WHERE rownumber = #counter
) t
)
end
declare #sql nvarchar(255) = 'select top '+cast(#counter as varchar(5))+' * from #temp'
EXECUTE sp_executesql #sql, N'#counter int', #counter = #counter;
However, I am not sure if this is the best way to deal with it and wonder if there is a better approach. There are many professionals here and I'd like to hear from them about what they think about my approach and how we can improve it. Any advice would be appreciated!
Try this:
select id, qty, checkvalue from (
select t1.*,
sum(t1.qty) over (partition by t2.id) [sum]
from #temp [t1] join #temp [t2] on t1.id <= t2.id
) a where checkvalue = [sum]
Smart self-join is all you need :)
For SQL Server 2012, and onwards, you can easily achieve this using ROWS BETWEEN in your OVER clause and the use of a CTE:
WITH Running AS(
SELECT *,
SUM(qty) OVER (ORDER BY id
ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS RunningQty
FROM #temp t)
SELECT id, qty, checkvalue
FROM Running
WHERE RunningQty <= checkvalue;
One basic improvement is to try & reduce the no. of iterations. You're incrementing by 1, but if you repurpose the logic behind binary searching, you'd get something close to this:
DECLARE #RoughAverage int = 1 -- Some arbitrary value. The closer it is to the real average, the faster things should be.
DECLARE #CheckValue int = (SELECT TOP 1 checkvalue FROM #temp)
DECLARE #Sum int = 0
WHILE 1 = 1 -- Refer to BREAK below.
BEGIN
SELECT TOP (#RoughAverage) #Sum = SUM(qty) OVER(ORDER BY id)
FROM #temp
ORDER BY id
IF #Sum = #CheckValue
BREAK -- Indicating you reached your objective.
ELSE
SET #RoughAverage = #CheckValue - #Sum -- Most likely incomplete like this.
END
For SQL 2008 you can use recursive cte. Top 1 with ties limits result with first combination. Remove it to see all combinations
with cte as (
select
*, rn = row_number() over (order by id)
from
#temp
)
, rcte as (
select
i = id, id, qty, sumV = qty, checkvalue, rn
from
cte
union all
select
a.id, b.id, b.qty, a.sumV + b.qty, a.checkvalue, b.rn
from
rcte a
join cte b on a.rn + 1 = b.rn
where
a.sumV < b.checkvalue
)
select
top 1 with ties id, qty, checkvalue
from (
select
*, needed = max(case when sumV = checkvalue then 1 else 0 end) over (partition by i)
from
rcte
) t
where
needed = 1
order by dense_rank() over (order by i)
When I try to alter the function below I get the following error message:
Only one expression can be specified in the select list when the
subquery is not introduced with EXISTS.
I guess it is probably because of select into select. But why does this select into select work separately ( not in function ) but not in function.
ALTER FUNCTION [dbo].[Getcurrentexchangerate] (#CurrencyFromId INT,
#CurrencyToId INT)
returns DECIMAL(13, 10)
AS
BEGIN
DECLARE #rate DECIMAL (13, 10)
DECLARE #dw INT
SET #dw = (SELECT Datepart(dw, Getdate()))
IF( #dw != 2 ) -- Monday
BEGIN
SET #rate = (SELECT TOP (1) [rate]
FROM currencyconversionrate
WHERE [currencyfromid] = #CurrencyFromId
AND [currencytoid] = #CurrencyToId
ORDER BY id DESC)
END
ELSE
BEGIN
SET #rate = (SELECT *
FROM (SELECT TOP(2) Row_number()
OVER (
ORDER BY id DESC) AS
rownumber,
rate
FROM currencyconversionrate
WHERE ( [currencyfromid] = 2
AND [currencytoid] = 5 )
ORDER BY id DESC) AS Rate
WHERE rownumber = 2)
END
IF( #rate IS NULL )
BEGIN
SET #rate = 1
END
RETURN #rate
END
See your "else" part
SET #rate = (SELECT *
FROM (SELECT TOP(2) Row_number()
OVER (
ORDER BY id DESC) AS
rownumber,
rate
FROM currencyconversionrate
WHERE ( [currencyfromid] = 2
AND [currencytoid] = 5 )
ORDER BY id DESC) AS Rate
WHERE rownumber = 2)
You're trying to select all fields from currencyconversionrate table, you can't do that, or do you want to select "RATE" column only?
Try changing to below:
SET #rate = (SELECT rate
FROM (SELECT TOP(1) Row_number()
OVER (
ORDER BY id DESC) AS
rownumber,
rate
FROM currencyconversionrate
WHERE ( [currencyfromid] = 2
AND [currencytoid] = 5 )
ORDER BY id DESC) AS Rate
WHERE rownumber = 2)
Say I have these rows,
InstrumentID
547
698
708
InstrumentID is not autogenerated column.
Say if I pass the parameter in procedure as 698, I should get previous value as 547 and next value as 708. How do I do this efficiently in SQL?
I have this procedure but it is not efficient (and not correct).
Alter PROCEDURE GetNextAndPreviousInsturmentID
(
#InstrumentID varchar(14),
#PreviousInstrumentID varchar(14) OUT,
#NextInstrumentID varchar(14) OUT
)
AS
BEGIN
Declare #RowNum int = 0
Select #RowNum = ROW_NUMBER() Over (Order by Cast(#InstrumentID as decimal(18))) From Documents Where InstrumentID = #InstrumentID
;With normal As
(
Select ROW_NUMBER() Over (Order by Cast(#InstrumentID as decimal(18))) as RowNum, Cast(InstrumentID as decimal(18)) as InstrumentID
From Documents
)
Select #PreviousInstrumentID = InstrumentID From normal
Where RowNum = #RowNum - 1
Select #NextInstrumentID = InstrumentID From normal
Where RowNum = #RowNum + 1
END
GO
Here is a simpler solution, still it's more efficient
SELECT P.PreviousID, N.NextID
FROM
(SELECT MAX(D.InstrumentID) PreviousID
FROM Documents D
WHERE InstrumentID < #InstrumentID) P
CROSS JOIN
(SELECT MIN(D.InstrumentID) NextID
FROM Documents D
WHERE InstrumentID > #InstrumentID) N
Try this:
Alter PROCEDURE GetNextAndPreviousInsturmentID
(
#InstrumentID varchar(14),
#PreviousInstrumentID varchar(14) OUT,
#NextInstrumentID varchar(14) OUT
)
AS
BEGIN
Declare #Ids TABLE(Id varchar(14))
;With normal As
(
--Numerate our rows
Select ROW_NUMBER() Over (Order by Cast(Documents.InstrumentID as decimal(18)) as RowNumber,
Documents.InstrumentID
From Documents
)
--Insert three rows from our table with our id and previos/next id
INSERT INTO #Ids(Id)
SELECT TOP(3) normal.InstrumentID
FROM normal
WHERE RowNumber >=
(
SELECT RowNumber - 1
FROM normal
WHERE normal.InstrumentID = #InstrumentID
)
ORDER BY normal.RowNumber
--select next and previos ids
SELECT #PreviousInstrumentID = Min(CAST(Id as decimal(18))),
#NextInstrumentID = MAX(CAST(Id as decimal(18)))
FROM #Ids
END
GO
In MS SQL 2012 we have new window functions like FIRST_VALUE and LAST_VALUE, unfortunately in sql 2008 these functions are missing.
WITH CTE AS (
SELECT rownum = ROW_NUMBER() OVER (ORDER BY p.LogDate), p.LogDate
FROM DeviceLogs p
)
SELECT prev.logdate PreviousValue, CTE.logdate, nex.logdate NextValue
FROM CTE
LEFT JOIN CTE prev ON prev.rownum = CTE.rownum - 1
LEFT JOIN CTE nex ON nex.rownum = CTE.rownum + 1
GO
select
LAG(InstrumentID) OVER (ORDER BY InstrumentID) PreviousValue,
InstrumentID,
LEAD(InstrumentID) OVER (ORDER BY InstrumentID) NextValue
from documents
Hi I think this will be much more efficient:
Select Next :
select top 1 ID from mytable
where ID >'698'
order by ID asc
Select Prev:
select top 1 ID from mytable
where ID <'698'
order by ID desc
I have some data like this:
row id
1 1
2 36
3 37
4 38
5 50
6 51
I would like to query it to look like this:
row id group
1 1 1
2 36 2
3 37 2
4 38 2
5 50 3
6 51 3
... so that I can GROUP BY where the numbers are consecutively sequential.
Also, looping/cursoring is out of the question since I'm working with a pretty large set of data, thanks.
;WITH firstrows AS
(
SELECT id, ROW_NUMBER() OVER (ORDER BY id) groupid
FROM Table1 a
WHERE id - 1 NOT IN (SELECT b.id FROM Table1 b)
)
SELECT id,
(
SELECT MAX(b.groupid)
FROM firstrows b
WHERE b.id <= a.id
) groupid
FROM Table1 a
with
data(row, id) as (
select *
from (
values
(1,1)
,(2,36)
,(3,37)
,(4,38)
,(5,50)
,(6,51)
) as foo(row, id)
),
anchor(row, id) as (
select row, id
from data d1
where not exists(select 0 from data d2 where d2.id = d1.id - 1)
)
select d1.*, dense_rank() over(order by foo.id) as thegroup
from
data d1
cross apply (select max(id) from anchor where anchor.id <= d1.id) as foo(id)
order by
d1.row
;
This solution does more work that is strictly necessary on the basis that there may be gaps in the sequence of row values, and on the assumption that those gaps should be ignored.
Set up test data:
DECLARE #table TABLE
(ROW INT,
id INT
)
INSERT #table
SELECT 1,1
UNION SELECT 2,36
UNION SELECT 3,37
UNION SELECT 4,38
UNION SELECT 5,50
UNION SELECT 6,51
Output query
;WITH grpCTE
AS
(
SELECT ROW, id,
ROW_NUMBER() OVER (ORDER BY ROW
) AS rn
FROM #table
)
,recCTE
AS
(
SELECT ROW, id, rn, 1 AS grp
FROM grpCTE
WHERE rn = 1
UNION ALL
SELECT g.row, g.id, g.rn, CASE WHEN g.id = r.id + 1 THEN r.grp ELSE r.grp + 1 END AS grp
FROM grpCTE AS g
JOIN recCTE AS r
ON g.rn = r.rn + 1
)
SELECT row, id, grp FROM recCTE
create table #temp
(
IDUnique int Identity(1,1),
ID int,
grp int
)
Insert into #temp(ID) Values(1)
Insert into #temp(ID) Values(36)
Insert into #temp(ID) Values(37)
Insert into #temp(ID) Values(38)
Insert into #temp(ID) Values(50)
Insert into #temp(ID) Values(51)
declare #IDUnique int
declare #PreviousUnique int
declare #ID int
declare #grp int
declare #Previous int
declare #Row int
DECLARE #getAccountID CURSOR SET #getAccountID = CURSOR FOR SELECT Row_Number() Over(Order by IDUnique) Row, IDUnique, ID From #temp
OPEN #getAccountID
FETCH NEXT FROM #getAccountID INTO #Row, #IDUnique, #ID
WHILE ##FETCH_STATUS = 0
BEGIN
IF(#Row = 1)
Begin
update #temp set grp = 1 Where IDUnique = #IDUnique
set #Previous = #ID
set #grp = 1
End
Else If (#Previous + 1 = #ID)
Begin
update #temp set grp = #grp Where IDUnique = #IDUnique
set #Previous = #ID
End
Else
Begin
set #Previous = #ID
set #grp = #grp + 1
update #temp set grp = #grp Where IDUnique = #IDUnique
End
FETCH NEXT FROM #getAccountID INTO #Row, #IDUnique, #ID
END
CLOSE #getAccountID
DEALLOCATE #getAccountID
Select * from #temp
Drop Table #temp
Select T.Id, T.Row, groupId as "Group", dr FROM tbrows T
Left Outer Join
(
Select min(id) as groupId,DENSE_RANK() over( order by min(id)) as dr, MIN(row-id) as d, Sum(1) as s FROM tbrows
Group BY (row-id)
) U
On (T.Id >= U.groupId) and (T.Id < U.groupId+U.s)
Order By T.Id
Table data look like this
id val
1 4
2 2
3 1
I want result of subtract valu of val field in one sql statement.
like it should be like 4-2-1 = 1 if order by id asc, 1-2-4 = -5 if order by id desc.
You can try this
DECLARE #Table TABLE(
ID INT,
Val INT
)
INSERT INTO #Table (ID,Val) SELECT 1, 4
INSERT INTO #Table (ID,Val) SELECT 2, 2
INSERT INTO #Table (ID,Val) SELECT 3, 1
SELECT SUM(Val * CASE WHEN RowID = 1 THEN 1 ELSE -1 END)
FROM (
SELECT *,
ROW_NUMBER() OVER (ORDER BY ID) RowID
FROM #Table
) sub
You can declare a variable and increment it in the select statement:
declare #sum float
select #sum = case when #sum is null then value else #sum - value end
from YourTable
order by id
select #sum
To reverse the subtraction order, change order by id to order by id desc.
if you want to use just the sql without temp tables or variables:
select fromid.val - sumid.val
from (
select val
from t
where id = (
select min(id)
from t
)
) fromid cross join (
select sum(val) as val
from t
where id > (
select min(id)
from t
)
) sumid