I have this query:
Select *
from
(Select
*
ROW_NUMBER() OVER (PARTITION BY TID ORDER BY TID) AS RowNumber
from
MyTable
where
Eid = 'C1') as a
where
a.RowNumber = 1
and it displays these results:
Column1 Column2 RowNumber
------------------------------
Value1 value2 1
I want to ignore the RowNumber column in the select statement and I don't want to list all columns in select query (100+ columns and given is just an example).
How to do this in SQL Server?
Well, you would have to list all the columns in the outer select, if you use a subquery and row_number() to get a unique row.
An alternative method uses a correlated subquery, but requires having some unique column in the table. If you have one:
select t.*
from mytable t
where t.col = (select max(t2.col) from mytable t2 where t2.tid = t.tid and t2.eid = 'C1');
With the right indexes, this can have better performance than the row_number() version.
If you don't have a unique column, you can do:
select t.*
from (select distinct tid from mytable where eid = 'C1') tc cross apply
(select top 1 t.*
from mytable t
where t.tid = tc.tid and t.eid = 'C1'
) t;
Wrap your query as a subquery and select specific columns from it like so:
SELECT x.Column1, x.Column2
FROM
(
Select * from (Select * ROW_NUMBER() OVER (PARTITION BY TID ORDER BY TID)
AS RowNumber from MyTable where Eid="C1") as a where a.RowNumber=1
) AS x
OR Change your original Select to:
Select a.[Column1], a.[Column2]
from
(
Select * ROW_NUMBER() OVER (PARTITION BY TID ORDER BY TID)
AS RowNumber from MyTable where Eid="C1"
) as a
Where a.RowNumber=1
Replace * from your query in clarify exactly columnd which you whant
select x.Column1, x.Column2 FROM (
Select * from (Select * ROW_NUMBER() OVER (PARTITION BY TID ORDER BY TID)
AS RowNumber from MyTable where Eid="C1") as a where a.RowNumber=1) AS x
Related
I need to get the record with the MAX id from this joined table, but I only need the top row to be joined with the main query on this subquery. How can I limit the subquery to only return one row? Previously the tran_state MAX was being returned which did not work correctly.
LEFT JOIN (
SELECT
tran_id
, MAX(id) AS max_tran_id
, MAX(DATETIME(created, 'America/New_York')) AS max_tran_created
, tran_state
FROM `prod.tran`
GROUP BY tran_id
) data ON t.id = data.tran_id
I attempted to modify the query like so but the tran_state is coming back as null.
LEFT JOIN (
SELECT
tran_state,
tran_id
FROM `prod.tran` WHERE ID IN (
SELECT
MAX(ID)
FROM `prod.tran` trans
WHERE trans.tran_id = transaction_id)
) data ON t.id = data.tran_id
You can use window functions:
LEFT JOIN
(SELECT t.*,
ROW_NUMBER() OVER (PARTITION BY t.tran_id ORDER BY t.id DESC) as seqnum
FROM `prod.tran` t
) data
ON t.id = data.tran_id AND t.seqnum = 1
Try this query.
SELECT *
FROM `prod.tran`
WHERE id IN (
SELECT MAX(id)
FROM `prod.tran`
GROUP BY tran_id
) a
I have this table:
I am trying to pull all records from this table for the max value in the DIST_NO column for every distinct ID in the left most column, but I still want to pull every record for each ID in which there are different Product_ID's as well.
I tried partitioning and using row_number, but I am having trouble at the moment.
Here are my desired results:
This is what my code looks like currently:
select *
from
(SELECT *,
ROW_NUMBER() OVER (PARTITION BY ID ORDER BY DIST_NO DESC) RN
FROM Table) V
WHERE RN<=3
you want the max(DIST_NO) for each ID, product_ID?
If so, you can:
SELECT
ID, product_ID, max(DIST_NO)
from table
group by ID, product_ID
If you want the detail rows related to the max row, you just need to join it back to your table:
Select
t.ID, max_dist_no, TRANSaction_ID , LINE_NO , PRODUCT_ID
from
table t inner join
(SELECT
ID, max(DIST_NO) as max_dist_no
from table
group by ID) mx on
t.ID = mx.ID and
t.DIST_NO = max_DIST_NO
Try
SELECT MT.ID
, MT.DIST_NO
, MT.TRANS_ID
, MT.LINE_NO
, MT.PRODUCT_ID
FROM MYTABLE MT
INNER JOIN (
SELECT T.ID, MAX(T.DIST_NO) as DIST_NO FROM MYTABLE T
GROUP BY T.ID
) MAX_MT ON MT.Id = MAX_MT.ID AND MT.DIST_NO = MAX_MT.DIST_NO
The sub query returns each combination of ID and Max value of DIST_NO:
SELECT T.ID, MAX(T.DIST_NO) as DIST_NO FROM MYTABLE T
GROUP BY T.ID
Joining this back to your original table will basically filter your original data-set by only these combinations of values.
Tested on PostgreSQL:
WITH t1 AS (
SELECT id, product_id, MAX(dist_no) AS dist_no
FROM test
GROUP BY 1,2)
SELECT t1.id, t1.dist_no, t2.trans_id, t2.line_no, t1.product_id
FROM test t2, t1
WHERE t1.id=t2.id AND t1.product_id=t2.product_id AND t1.dist_no=t2.dist_no
Use rank() or dense_rank():
select t.*
from (SELECT t.*
RANK() OVER (PARTITION BY ID ORDER BY DIST_NO DESC) as seqnum
FROM Table t
) t
WHERE seqnum = 1;
This is almost a literal translation of your request:
I am trying to pull all records from this table for the max value in
the DIST_NO column for every distinct ID in the left most column.
you can try something like this one :). (But is your result correct? I think there is little mistake in TRANS_ID...)
DECLARE #ExampleTable TABLE
(ID INT,
DIST_NO INT,
TRANS_ID INT,
LINE_NO INT,
PRODUCT_ID INT)
INSERT INTO #ExampleTable
( ID, DIST_NO, TRANS_ID,LINE_NO, PRODUCT_ID )
VALUES ( 102657, 1, 1105365, 1, 109119 ),
( 102657, 1, 1105366, 2, 109114 ),
( 102657, 2, 1105365, 1, 109119 ),
( 102657, 2, 1105366, 2, 109114 ),
( 104371, 1, 1190538, 1, 110981 ),
( 104371, 2, 1190538, 1, 110981 )
;WITH CTE AS ( SELECT DISTINCT ID, LINE_NO
FROM #ExampleTable)
SELECT a.ID,
x.DIST_NO,
x.TRANS_ID,
x.LINE_NO,
x.PRODUCT_ID
FROM CTE a
CROSS APPLY (SELECT TOP 1 *
FROM #ExampleTable f
WHERE a.ID = f.ID AND
a.LINE_NO = f. LINE_NO
ORDER BY DIST_NO DESC) x
What I am trying to accomplish:
Dataset 1
Name1
Name2
Name3
Dataset 2
Number1
Number2
Number3
will become 2 columns:
dataset1 dataset2
Name1 Number1
Name2 Number2
Name3 Number3
My datasets 1 & 2 will always have equal rows.
Which name linked to which number I don't care as long as two names are not linked to the same number and vice versa.
How can I solve this with SQL / SQL Server ?
If you don't want to add an identity column to the tables, you can use the ROW_NUMBER() function like this:
SELECT
T1.Col1,
T2.Col1
FROM
(SELECT Col1, ROW_NUMBER() OVER (ORDER BY Col1) AS N FROM Table1) T1
INNER JOIN
(SELECT Col1, ROW_NUMBER() OVER (ORDER BY Col1) AS N FROM Table2) T2
ON T1.N = T2.N
Here, replace Table1 and Table2 with the name of your tables, and replace Col1 with the name of the column (or columns) that you want to output from the two tables.
Add identity columns to both the tables and perform join on basis of these column
ALTER TABLE Table1
ADD ID INT IDENTITY(1,1) NOT NULL
ALTER TABLE Table2
ADD ID INT IDENTITY(1,1) NOT NULL
SELECT Table1.dataset1col , Table2.dataset2Col
From Table1 INNER JOIN Table2
ON Table1.ID = Table2.ID
This may work for you :
;WITH cte1 (name, rn)
AS (SELECT Name,
row_number()
OVER(
ORDER BY Name) rn
FROM Dataset1),
cte2 (Number, rn)
AS (SELECT Number,
row_number()
OVER(
ORDER BY Number) rn
FROM Dataset2)
SELECT name,
Number
FROM cte1
JOIN cte2
ON cte1.rn = cte2.rn
WITH Table1 AS
(
SELECT ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Dataset1) as Rnk,Dataset1
FROM TA1
)
With Table2 AS
(
SELECT ROW_NUMBER() OVER (PARTITION BY ID ORDER BY Dataset2) as Rnk, Dataset2
FROM TA2
)
Select Table.Dataset1 as 'DataSet1', Table2.DataSet2 as 'DataSet2'
From Table1
inner join Table2 on Table1.Rnk = Table2.Rnk
Because you haven't added table name so I considered it as TA1 and TA2.
Another way of writing the query is:
select row_number() over (order by Names asc) as rownum,
Names
into #Temp1
from NameTable
select row_number() over (order by Numbers asc) as rownum,
Numbers
into #Temp2
from NumberTable
select Names, Numbers
from #Temp1
inner join #Temp2 on #Temp1.rownum = #Temp2.rownum
Demo
There are 3 possible solutions to this.
First: Use following trick (Warning: Use this in case of small datasets)
SELECT DISTINCT tbl1.col1, tbl2.col2
FROM
(SELECT FirstName AS col1, ROW_NUMBER() OVER (ORDER BY FirstName) Number FROM dbo.User) tbl1
INNER JOIN
(SELECT LastName AS col2, ROW_NUMBER() OVER (ORDER BY LastName) Number FROM dbo.User) tbl2
ON tbl1.Number = tbl2.Number
Second: Use variable tables to store result temporarily. This solution is for relatively large datasets. (approx records to 100s)
Third:
Use identitfy field in both tables as already mentioned by mmhasannn. But i will prefer this method least, as we need to modify our DB structure.
RECOMMENDED: Use variable tables approach
Need to find in databse max value, but then i need read other values in columns.
Can this be done with one SQL command or I have to use this two commands?
SELECT MAX(id) FROM Table;
SELECT * FROM Table WHERE id = $value;
where $value is variable from 1st command
select * from your_table
where id = (select max(id) from your_table)
or
select t1.* from your_table t1
inner join
(
select max(id) as mid
from your_table
)
t2 on t1.id = t2.mid
Probably the simplest way is:
select *
from t
order by id
limit 1
Or use top 1 or where rownum = 1 or whatever is the right logic for your database.
Note: this only returns one row. If you have duplicate such rows, then comparison to the maximum will give you all of them.
Also, if you are using a database that supports window functions:
select *
from (select t.*, row_number() over (order by id desc) as seqnum
from t
) t
where seqnum = 1;
In my table I need to know if each ID has one and only one ID_name. How can I write such query?
I tried:
select ID, count(distinct ID_name) as count_name
from table
group by ID
having count_name > 1
But it takes forever to run.
Any thoughts?
select ID
from YourTable
group by
ID
having count(distinct ID_name) > 1
or
select *
from YourTable yt1
where exists
(
select *
from YourTable yt2
where yt1.ID = yt2.ID
and yt1.ID_Name <> yt2.ID_Name
)
Now, most ID columns are defined as primary key and are unique. So in a regular database you'd expect both queries to return an empty set.
select tt.ID,max(tt.myRank)
from
(
select
ip.ID,ip.ID_name,
ROW_Number() over (partition by ip.ID,ip.ID_nameorder by ip.ID) as myRank
from YourTable ip
) tt
group by tt.ID
This gives you every ID with it's total number of ID_Name
If you want only those ID's which have more than one name associated just add a where clause
e.g.
select tt.ID,max(tt.myRank)
from
(
select
ip.ID,ip.ID_name,
ROW_NUMBER() over (partition by ip.ID,ip.ID_nameorder by ip.ID) as myRank
from YourTable ip
) tt
**where tt.myRank > 1**
group by tt.ID