How to find the first nearest value up and down in SQL? - sql

I have table like this:
When I set id =4 , the results I need are:
Note that I selected the ID=4 and the two nearest values from both sides .
How can write sql code for do it?

You can use LEAD() function , that selects the next value by a specific order , like this:
Note that LEAD was only introduced to SQL-Server 2012+.
SELECT s.id,s.name,s.number
FROM (
SELECT t.*
LEAD(t.id,1) OVER(ORDER BY t.Number DESC) as Next_val,
LEAD(t.id,1) OVER(ORDER BY t.Number) as Last_val
FROM YourTable t) s
WHERE 4 IN(s.id,next_Val,s.last_val)
You can replace 4 with your desired ID or with a parameter .
EDIT: A little explanation - LEAD function provides a way to access the next row, without the use of a SELF JOIN or a sub query , it orders the results by the order you provided inside the OVER() clause, and select the value inside the parentheses - LEAD(value) that belong to the record above the current record that is being processed. So, this query selects each ID , and the ID that belongs to the nearest value up and down , and then check if one of them is your desired ID .

declare #id int = 4
select sn.*
from table sn
inner join
(
select top 2 sn_prev.*
from table sn_prev
where id <= #id
order by id desc
) sp on sp.id= sn.id
union
select sn.*
from table sn
inner join
(
select top 1 sn_prev.*
from table sn_prev
where id > #id
order by id
) sp on sp.id = sn.id

you can use MIN() and MAX() function in sql.

Related

Listing multiple columns in a single row in SQL

(select ID,EXTERNAL_TRANSACTION_ID,EXTERNAL_TRANSACTION_TYPE,ROW_NUMBER() OVER(PARTITION BY EXTERNAL_TRANSACTION_ID ORDER BY ID ) AS SEQNUM
from AC_POS_TRANSACTION_TRK aptt WHERE [RESULT] ='Success'
GROUP BY ID, EXTERNAL_TRANSACTION_ID,EXTERNAL_TRANSACTION_TYPE )
Hello,
On above query, I want to get rows of transaction id's which has seqnum=1 and seqnum=2
But if that transaction id has no second row (seqnum=2), I dont want to get any row for that transaction id.
Thanks!!
Something like this
Not 100% sure if this is correct without you table definition, but my understanding is that you want to EXCLUDE records if that record has an entry with seqnum=2 -- you can't use a where clause alone because that would still return seqnum = 1.
You can use an exists /not exists or in/not in clause like this
(select ID,EXTERNAL_TRANSACTION_ID,EXTERNAL_TRANSACTION_TYPE,ROW_NUMBER() OVER(PARTITION BY EXTERNAL_TRANSACTION_ID ORDER BY ID ) AS SEQNUM
from AC_POS_TRANSACTION_TRK aptt WHERE [RESULT] ='Success'
and not exists ( select 1 from AC_POS_TRANSACTION_TRK a where a.id = aptt.id
and a.seqnum = 2)
GROUP BY ID, EXTERNAL_TRANSACTION_ID,EXTERNAL_TRANSACTION_TYPE )
basically what this does is it excludes records if a record exists as specified in the NOT EXISTS query.
One option you can try is to add a count of rows per group using the same partioning critera and then filter accordingly. Not entirely sure about your query without seeing it in context and with sample data - there's no aggregation so why use group by?
However can you try something along these lines
select * from (
select ID,EXTERNAL_TRANSACTION_ID,EXTERNAL_TRANSACTION_TYPE,
Row_Number() over(partition by EXTERNAL_TRANSACTION_ID order by ID) as SEQNUM,
Count(*) over(partition by EXTERNAL_TRANSACTION_ID) Qty
from AC_POS_TRANSACTION_TRK
where [RESULT] ='Success'
)x
where SEQNUM in (1,2) and Qty>1
This should do the job.
With Qry As (
-- Your original query goes here
),
Select Qry.*
From Qry
Where Exists (
Select *
From Qry Qry1
Where Qry1.EXTERNAL_TRANSACTION_ID = Qry.EXTERNAL_TRANSACTION_ID
And Qry1.SEQNUM = 1
)
And Exists (
Select *
From Qry Qry2
Where Qry2.EXTERNAL_TRANSACTION_ID = Qry.EXTERNAL_TRANSACTION_ID
And Qry2.SEQNUM = 2
)
BTW, your original query looks problematic to me, specifically I think that instead of a GROUP BY columns those columns should be in the PARTITION BY clause of the OVER statement, but without knowing more about the table structures and what you're trying to achieve, I could not say for sure.

How to find Max value in a column in SQL Server 2012

I want to find the max value in a column
ID CName Tot_Val PName
--------------------------------
1 1 100 P1
2 1 10 P2
3 2 50 P2
4 2 80 P1
Above is my table structure. I just want to find the max total value only from the table. In that four row ID 1 and 2 have same value in CName but total val and PName has different values. What I am expecting is have to find the max value in ID 1 and 2
Expected result:
ID CName Tot_Val PName
--------------------------------
1 1 100 P1
4 2 80 P1
I need result same as like mention above
select Max(Tot_Val), CName
from table1
where PName in ('P1', 'P2')
group by CName
This is query I have tried but my problem is that I am not able to bring PName in this table. If I add PName in the select list means it will showing the rows doubled e.g. Result is 100 rows but when I add PName in selected list and group by list it showing 600 rows. That is the problem.
Can someone please help me to resolve this.
One possible option is to use a subquery. Give each row a number within each CName group ordered by Tot_Val. Then select the rows with a row number equal to one.
select x.*
from ( select mt.ID,
mt.CName,
mt.Tot_Val,
mt.PName,
row_number() over(partition by mt.CName order by mt.Tot_Val desc) as No
from MyTable mt ) x
where x.No = 1;
An alternative would be to use a common table expression (CTE) instead of a subquery to isolate the first result set.
with x as
(
select mt.ID,
mt.CName,
mt.Tot_Val,
mt.PName,
row_number() over(partition by mt.CName order by mt.Tot_Val desc) as No
from MyTable mt
)
select x.*
from x
where x.No = 1;
See both solutions in action in this fiddle.
You can search top-n-per-group for this kind of a query.
There are two common ways to do it. The most efficient method depends on your indexes and data distribution and whether you already have another table with the list of all CName values.
Using ROW_NUMBER
WITH
CTE
AS
(
SELECT
ID, CName, Tot_Val, PName,
ROW_NUMBER() OVER (PARTITION BY CName ORDER BY Tot_Val DESC) AS rn
FROM table1
)
SELECT
ID, CName, Tot_Val, PName
FROM CTE
WHERE rn=1
;
Using CROSS APPLY
WITH
CTE
AS
(
SELECT CName
FROM table1
GROUP BY CName
)
SELECT
A.ID
,A.CName
,A.Tot_Val
,A.PName
FROM
CTE
CROSS APPLY
(
SELECT TOP(1)
table1.ID
,table1.CName
,table1.Tot_Val
,table1.PName
FROM table1
WHERE
table1.CName = CTE.CName
ORDER BY
table1.Tot_Val DESC
) AS A
;
See a very detailed answer on dba.se Retrieving n rows per group
, or here Get top 1 row of each group
.
CROSS APPLY might be as fast as a correlated subquery, but this often has very good performance (and better than ROW_NUMBER():
select t.*
from t
where t.tot_val = (select max(t2.tot_val)
from t t2
where t2.cname = t.cname
);
Note: The performance depends on having an index on (cname, tot_val).

SQL Oracle Find Max of count

I have this table called item:
| PERSON_id | ITEM_id |
|------------------|----------------|
|------CP2---------|-----A03--------|
|------CP2---------|-----A02--------|
|------HB3---------|-----A02--------|
|------BW4---------|-----A01--------|
I need an SQL statement that would output the person with the most Items. Not really sure where to start either.
I advice you to use inner query for this purpose. the inner query is going to include group by and order by statement. and outer query will select the first statement which has the most items.
SELECT * FROM
(
SELECT PERSON_ID, COUNT(*) FROM TABLE1
GROUP BY PERSON_ID
ORDER BY 2 DESC
)
WHERE ROWNUM = 1
here is the fiddler link : http://sqlfiddle.com/#!4/4c4228/5
Locating the maximum of an aggregated column requires more than a single calculation, so here you can use a "common table expression" (cte) to hold the result and then re-use that result in a where clause:
with cte as (
select
person_id
, count(item_id) count_items
from mytable
group by
person_id
)
select
*
from cte
where count_items = (select max(count_items) from cte)
Note, if more than one person shares the same maximum count; more than one row will be returned bu this query.

Max() not filtering out MIN()

when I use run the query below, it returns duplicate StockNo's because some of them have duplicate WorkInProgress codes (FiWipStatus Code).
Is there a way to exclude the record based on the the MIN() on rowlastupdated?
as always, appreciate any help!
SELECT dbo.InventoryVehicle.StockNo, dbo.VehicleSales.FiWipStatusCode,
MAX(dbo.VehicleSales.RowLastUpdated) AS Expr1
FROM dbo.VehicleSales RIGHT OUTER JOIN
dbo.InventoryVehicle ON dbo.VehicleSales.StockNo = dbo.InventoryVehicle.StockNo
GROUP BY dbo.InventoryVehicle.StockNo, dbo.VehicleSales.FiWipStatusCode,
dbo.VehicleSales.RowLastUpdated
If I got it correctly, you need to get the records based on their last update date and time (which is RowLastUpdated). if so, you can do something like this :
SELECT
iv.StockNo
, vs.FiWipStatusCode
, vs.RowLastUpdated
FROM (
SELECT
iv.StockNo
, vs.FiWipStatusCode
, vs.RowLastUpdated
, ROW_NUMBER() OVER(PARTITION BY iv.StockNo ORDER BY vs.RowLastUpdated DESC) AS RN
FROM
VehicleSales vs
LEFT JOIN InventoryVehicle iv ON vs.StockNo = iv.StockNo
) D
WHERE
RN = 1
where ROW_NUMBER() will number the rows based on StockNo and order them based on RowLastUpdated in DESC. So, the first row of each distinct StockNo will be the MAX() datetime in your aggregation query. if you want to get the MIN() just change the order to ASC

SQL query to select distinct row with minimum value

I want an SQL statement to get the row with a minimum value.
Consider this table:
id game point
1 x 5
1 z 4
2 y 6
3 x 2
3 y 5
3 z 8
How do I select the ids that have the minimum value in the point column, grouped by game? Like the following:
id game point
1 z 4
2 y 5
3 x 2
Use:
SELECT tbl.*
FROM TableName tbl
INNER JOIN
(
SELECT Id, MIN(Point) MinPoint
FROM TableName
GROUP BY Id
) tbl1
ON tbl1.id = tbl.id
WHERE tbl1.MinPoint = tbl.Point
This is another way of doing the same thing, which would allow you to do interesting things like select the top 5 winning games, etc.
SELECT *
FROM
(
SELECT ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Point) as RowNum, *
FROM Table
) X
WHERE RowNum = 1
You can now correctly get the actual row that was identified as the one with the lowest score and you can modify the ordering function to use multiple criteria, such as "Show me the earliest game which had the smallest score", etc.
This will work
select * from table
where (id,point) IN (select id,min(point) from table group by id);
As this is tagged with sql only, the following is using ANSI SQL and a window function:
select id, game, point
from (
select id, game, point,
row_number() over (partition by game order by point) as rn
from games
) t
where rn = 1;
Ken Clark's answer didn't work in my case. It might not work in yours either. If not, try this:
SELECT *
from table T
INNER JOIN
(
select id, MIN(point) MinPoint
from table T
group by AccountId
) NewT on T.id = NewT.id and T.point = NewT.MinPoint
ORDER BY game desc
SELECT DISTINCT
FIRST_VALUE(ID) OVER (Partition by Game ORDER BY Point) AS ID,
Game,
FIRST_VALUE(Point) OVER (Partition by Game ORDER BY Point) AS Point
FROM #T
SELECT * from room
INNER JOIN
(
select DISTINCT hotelNo, MIN(price) MinPrice
from room
Group by hotelNo
) NewT
on room.hotelNo = NewT.hotelNo and room.price = NewT.MinPrice;
This alternative approach uses SQL Server's OUTER APPLY clause. This way, it
creates the distinct list of games, and
fetches and outputs the record with the lowest point number for that game.
The OUTER APPLY clause can be imagined as a LEFT JOIN, but with the advantage that you can use values of the main query as parameters in the subquery (here: game).
SELECT colMinPointID
FROM (
SELECT game
FROM table
GROUP BY game
) As rstOuter
OUTER APPLY (
SELECT TOP 1 id As colMinPointID
FROM table As rstInner
WHERE rstInner.game = rstOuter.game
ORDER BY points
) AS rstMinPoints
This is portable - at least between ORACLE and PostgreSQL:
select t.* from table t
where not exists(select 1 from table ti where ti.attr > t.attr);
Most of the answers use an inner query. I am wondering why the following isn't suggested.
select
*
from
table
order by
point
fetch next 1 row only // ... or the appropriate syntax for the particular DB
This query is very simple to write with JPAQueryFactory (a Java Query DSL class).
return new JPAQueryFactory(manager).
selectFrom(QTable.table).
setLockMode(LockModeType.OPTIMISTIC).
orderBy(QTable.table.point.asc()).
fetchFirst();
Try:
select id, game, min(point) from t
group by id