I am trying to have row_number based on custom grouping but I am not able to produce it.
Below is my Query
CREATE TABLE mytbl (wid INT, id INT)
INSERT INTO mytbl Values(1,1),(2,1),(3,0),(4,2),(5,3)
Current Output
wid id
1 1
2 1
3 0
4 2
5 3
Query
SELECT *, RANK() OVER(PARTITION BY wid, CASE WHEN id = 0 THEN 0 ELSE 1 END ORDER BY ID)
FROM mytbl
I would like to rank the rows based on custom condition like if ID is 0 then I have start new group until I have non 0 ID.
Expected Output
wid id RN
1 1 1
2 1 1
3 0 1
4 2 2
5 3 2
Guessing here, as we don't have much clarification, but perhaps this:
SELECT wid,
id,
COUNT(CASE id WHEN 0 THEN 1 END) OVER (ORDER BY wid ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING) +1 AS [Rank]
FROM mytbl ;
If I understand you correctly, you may use the next approach. Note, that you need to have an ordering column (I assume this is wid column):
Statement:
;WITH ChangesCTE AS (
SELECT
*,
CASE WHEN LAG(id) OVER (ORDER BY wid) = 0 THEN 1 ELSE 0 END AS ChangeIndex
FROM mytbl
), GroupsCTE AS (
SELECT
*,
SUM(ChangeIndex) OVER (ORDER BY wid) AS GroupIndex
FROM ChangesCTE
)
SELECT
wid,
id,
DENSE_RANK() OVER (ORDER BY GroupIndex) AS Rank
FROM GroupsCTE
Result:
wid id Rank
1 1 1
2 1 1
3 0 1
4 2 2
5 3 2
without much clarification on the logic required, my understanding is you want to increase the Rank by 1 whenever id = 0
select wid, id,
[Rank] = sum(case when id = 0 then 1 else 0 end) over(order by wid)
+ case when id <> 0 then 1 else 0 end
from mytbl
Try this,
CREATE TABLE #mytbl (wid INT, id INT)
INSERT INTO #mytbl Values(1,1),(2,1),(3,0)
,(4,2),(5,3),(6,0),(7,4),(8,5),(9,6)
;with CTE as
(
select *,ROW_NUMBER()over(order by wid)rn
from #mytbl where id=0
)
,CTE1 as
(
select max(rn)+1 ExtraRN from CTE
)
select a.* ,isnull(ca.rn,ca1.ExtraRN) from #mytbl a
outer apply(select top 1 * from CTE b
where a.wid<=b.wid )ca
cross apply(select ExtraRN from CTE1)ca1
drop table #mytbl
Here both OUTER APPLY and CROSS APPLY will not increase cardianility estimate.It will always return only one rows.
Related
I have a table which looks like this
ID A B C
1 1 0 0
1 1 0 0
2 1 1 0
2 1 1 0
How can I remove the duplicated rows in SQL so that I am left with a table that looks like this:
ID A B C
1 1 0 0
2 1 1 0
use row_number()
with cte as
(
select *, row_number() over(partition by id order by id) as rn
from tablename
)
delete from cte where rn<>1
select distinct * from <table_name>
This is the simplest way.
I have a table like so
ID OrdID Value
1 1 0
2 2 0
3 1 1
4 2 1
5 1 1
6 2 0
7 1 0
8 2 0
9 2 1
10 1 0
11 2 0
I want to get the count of consecutive value where the value is 0. Using the example above the result will be 3 (Rows 6, 7 and 8). I am using sql server 2008 r2.
I am going to presume that id is unique and increasing. You can get counts of consecutive values by using the different of row numbers. The following counts all sequences:
select grp, value, min(id), max(id), count(*) as cnt
from (select t.*,
(row_number() over (order by id) - row_number() over (partition by value order by id)
) as grp
from table t
) t
group by grp, value;
If you want the longest sequence of 0s:
select top 1 grp, value, min(id), max(id), count(*) as cnt
from (select t.*,
(row_number() over (order by id) - row_number() over (partition by value order by id)
) as grp
from table t
) t
group by grp, value
having value = 0
order by count(*) desc
A query using not exists to find consecutive 0s
select top 1 min(t2.id), max(t2.id), count(*)
from mytable t
join mytable t2 on t2.id <= t.id
where not exists (
select 1 from mytable t3
where t3.id between t2.id and t.id
and t3.value <> 0
)
group by t.id
order by count(*) desc
http://sqlfiddle.com/#!3/52989/3
I need to select data base upon three conditions
Find the latest date (StorageDate Column) from the table for each record
See if there is more then one entry for date (StorageDate Column) found in first step for same ID (ID Column)
and then see if DuplicateID is = 2
So if table has following data:
ID |StorageDate | DuplicateTypeID
1 |2014-10-22 | 1
1 |2014-10-22 | 2
1 |2014-10-18 | 1
2 |2014-10-12 | 1
3 |2014-10-11 | 1
4 |2014-09-02 | 1
4 |2014-09-02 | 2
Then I should get following results
ID
1
4
I have written following query but it is really slow, I was wondering if anyone has better way to write it.
SELECT DISTINCT(TD.RecordID)
FROM dbo.MyTable TD
JOIN (
SELECT T1.RecordID, T2.MaxDate,COUNT(*) AS RecordCount
FROM MyTable T1 WITH (nolock)
JOIN (
SELECT RecordID, MAX(StorageDate) AS MaxDate
FROM MyTable WITH (nolock)
GROUP BY RecordID)T2
ON T1.RecordID = T2.RecordID AND T1.StorageDate = T2.MaxDate
GROUP BY T1.RecordID, T2.MaxDate
HAVING COUNT(*) > 1
)PT ON TD.RecordID = PT.RecordID AND TD.StorageDate = PT.MaxDate
WHERE TD.DuplicateTypeID = 2
Try this and see how the performance goes:
;WITH
tmp AS
(
SELECT *,
RANK() OVER (PARTITION BY ID ORDER BY StorageDate DESC) AS StorageDateRank,
COUNT(ID) OVER (PARTITION BY ID, StorageDate) AS StorageDateCount
FROM MyTable
)
SELECT DISTINCT ID
FROM tmp
WHERE StorageDateRank = 1 -- latest date for each ID
AND StorageDateCount > 1 -- more than 1 entry for date
AND DuplicateTypeID = 2 -- DuplicateTypeID = 2
You can use analytic function rank , can you try this query ?
Select recordId from
(
select *, rank() over ( partition by recordId order by [StorageDate] desc) as rn
from mytable
) T
where rn =1
group by recordId
having count(*) >1
and sum( case when duplicatetypeid =2 then 1 else 0 end) >=1
How to count the change in a sql server column like I have Ignition value
Ignition
1
1
0
1
1
1
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
1
I want to count change only it is from 0 to 1 to make occurrence 1. It can also be from 1 to 0 for the occurrence to be 1.
Step 1: use the Row_Number() function to provide a complete (un-broken) sequence of numbers, according to our order
SELECT ignition
, id
, Row_Number() OVER (ORDER BY id ASC) As row_num
FROM your_table
Step 4: Make this a Common-Table Expression (CTE) so we can refer to the derived row_num column
; WITH cte AS (
SELECT ignition
, id
, Row_Number() OVER (ORDER BY id ASC) As row_num
FROM your_table
)
SELECT ignition
, id
, row_num
FROM cte
Step 3: join this table back to itself matching on the next/previous row
; WITH cte AS (
SELECT ignition
, id
, Row_Number() OVER (ORDER BY id ASC) As row_num
FROM your_table
)
SELECT c1.ignition As c1_ignition
, c2.ignition As c2_ignition
FROM cte As c1
LEFT
JOIN cte As c2
ON c2.row_num = c1.row_num + 1
Step 4: Filter the results to show those where the values aren't the same
; WITH cte AS (
SELECT ignition
, id
, Row_Number() OVER (ORDER BY id ASC) As row_num
FROM your_table
)
SELECT c1.ignition As c1_ignition
, c2.ignition As c2_ignition
FROM cte As c1
LEFT
JOIN cte As c2
ON c2.row_num = c1.row_num - 1
WHERE c1.ignition <> c2.ignition
Step 5: ...
Step 6: profit!
Not sure if you want a solution that works in both 2008 and 2012 as you have both tags, but in 2012 (doesn't work in 2008) we did get LAG() and LEAD() so a SUM() of [Change] in the query below will do it for 2012. You'll have to decide how to handle the first value (which obviously doesn't have a previous value), current state it counts as a change.
SELECT [Id]
, [Ignition]
, LAG([Ignition]) OVER(ORDER BY [Id]) [Previous]
, CASE WHEN LAG([Ignition]) OVER(ORDER BY [Id]) = [Ignition] THEN 0 ELSE 1 END [Change]
FROM [dbo].[Table]
ORDER BY Id;
For 2008 a self-join should produce the same result.
SELECT [T1].[Id]
, [T1].[Ignition]
, [T2].[Ignition] [Previous]
, CASE WHEN [T1].[Ignition] = [T2].[Ignition] THEN 0 ELSE 1 END [Change]
FROM [dbo].[Table] [T1]
LEFT JOIN [dbo].[Table] [T2] ON [T1].[Id] = ([T2].[Id] + 1)
ORDER BY [T1].[Id];
declare #t table(id int identity(1,1), ignition bit)
insert #t values(1),(0),(1),(1)
declare #Ignition varchar(max) = ''
select #Ignition = #Ignition + cast(Ignition as char(1))
from #t order by id
select #ignition
select len(replace(replace(replace(#Ignition, '10', 'x')
+ replace(#Ignition, '01', 'x'), 1, ''), 0, ''))
Result:
2
Simplest and shortest way for SQL server 2008 I know is:
with cte as (
select
row_number() over(partition by Ignition order by Id) as rn1,
row_number() over(order by Id) as rn2
from Table1
)
select count(distinct rn2 - rn1) - 1
from cte
Or, as #MartinSmith pointed out:
with cte as (
select
row_number() over(order by Ignition, Id) as rn1,
row_number() over(order by Id) as rn2
from Table1
), cte2 as (
select distinct Ignition, rn2 - rn1
from cte
)
select count(*) - 1
from cte2
for SQL Server 2012 you can use lag() (or lead()) function:
;with cte as (
select
lag(Ignition) over(order by Id) as prev,
Ignition as cur
from Table1
)
select count(case when cur <> prev then 1 end)
from cte;
sql fiddle demo
I have a table
Val | Number
08 | 1
09 | 1
10 | 1
11 | 3
12 | 0
13 | 1
14 | 1
15 | 1
I need to return the last values where Number = 1 (however many that may be) until Number changes, but do not need the first instances where Number = 1. Essentially I need to select back until Number changes to 0 (15, 14, 13)
Is there a proper way to do this in MSSQL?
Based on following:
I need to return the last values where Number = 1
Essentially I need to select back until Number changes to 0 (15, 14,
13)
Try (Fiddle demo ):
select val, number
from T
where val > (select max(val)
from T
where number<>1)
EDIT: to address all possible combinations (Fiddle demo 2)
;with cte1 as
(
select 1 id, max(val) maxOne
from T
where number=1
),
cte2 as
(
select 1 id, isnull(max(val),0) maxOther
from T
where val < (select maxOne from cte1) and number<>1
)
select val, number
from T cross join
(select maxOne, maxOther
from cte1 join cte2 on cte1.id = cte2.id
) X
where val>maxOther and val<=maxOne
I think you can use window functions, something like this:
with cte as (
-- generate two row_number to enumerate distinct groups
select
Val, Number,
row_number() over(partition by Number order by Val) as rn1,
row_number() over(order by Val) as rn2
from Table1
), cte2 as (
-- get groups with Number = 1 and last group
select
Val, Number,
rn2 - rn1 as rn1, max(rn2 - rn1) over() as rn2
from cte
where Number = 1
)
select Val, Number
from cte2
where rn1 = rn2
sql fiddle demo
DEMO: http://sqlfiddle.com/#!3/e7d54/23
DDL
create table T(val int identity(8,1), number int)
insert into T values
(1),(1),(1),(3),(0),(1),(1),(1),(0),(2)
DML
; WITH last_1 AS (
SELECT Max(val) As val
FROM t
WHERE number = 1
)
, last_non_1 AS (
SELECT Coalesce(Max(val), -937) As val
FROM t
WHERE EXISTS (
SELECT val
FROM last_1
WHERE last_1.val > t.val
)
AND number <> 1
)
SELECT t.val
, t.number
FROM t
CROSS
JOIN last_1
CROSS
JOIN last_non_1
WHERE t.val <= last_1.val
AND t.val > last_non_1.val
I know it's a little verbose but I've deliberately kept it that way to illustrate the methodolgy.
Find the highest val where number=1.
For all values where the val is less than the number found in step 1, find the largest val where the number<>1
Finally, find the rows that fall within the values we uncovered in steps 1 & 2.
select val, count (number) from
yourtable
group by val
having count(number) > 1
The having clause is the key here, giving you all the vals that have more than one value of 1.
This is a common approach for getting rows until some value changes. For your specific case use desc in proper spots.
Create sample table
select * into #tmp from
(select 1 as id, 'Alpha' as value union all
select 2 as id, 'Alpha' as value union all
select 3 as id, 'Alpha' as value union all
select 4 as id, 'Beta' as value union all
select 5 as id, 'Alpha' as value union all
select 6 as id, 'Gamma' as value union all
select 7 as id, 'Alpha' as value) t
Pull top rows until value changes:
with cte as (select * from #tmp t)
select * from
(select cte.*, ROW_NUMBER() over (order by id) rn from cte) OriginTable
inner join
(
select cte.*, ROW_NUMBER() over (order by id) rn from cte
where cte.value = (select top 1 cte.value from cte order by cte.id)
) OnlyFirstValueRecords
on OriginTable.rn = OnlyFirstValueRecords.rn and OriginTable.id = OnlyFirstValueRecords.id
On the left side we put an original table. On the right side we put only rows whose value is equal to the value in first line.
Records in both tables will be same until target value changes. After line #3 row numbers will get different IDs associated because of the offset and will never be joined with original table:
LEFT RIGHT
ID Value RN ID Value RN
1 Alpha 1 | 1 Alpha 1
2 Alpha 2 | 2 Alpha 2
3 Alpha 3 | 3 Alpha 3
----------------------- result set ends here
4 Beta 4 | 5 Alpha 4
5 Alpha 5 | 7 Alpha 5
6 Gamma 6 |
7 Alpha 7 |
The ID must be unique. Ordering by this ID must be same in both ROW_NUMBER() functions.