THIS IS NOT ASKING HOW TO USE SUM() AND GROUP BY
I have two rows in tableA
ID VALUE
1 100
1 200
I want tableA:
ID VALUE
1 300
Note that I want to
delete the original two records in tableA
and replace them by the new record in tableA
Is this related to merge function?
I only want to work on tableA, don't want to create any new tables.
How about MERGE:
;with cte as (
select t.*,
row_number() over (partition by id order by id) as rn,
sum(value) over (partition by id) as total_value
from your_table t
)
merge into cte as t
using cte as t2
on (
t.id = t2.id
and t.rn = t2.rn
and t.rn = 1
)
when matched then update set t.value = t2.total_value
when not matched by source then delete;
Demo
Related
I have a table that contains duplicated ItemId. I am using CTE to remove the duplicate records and keep only single record for each item. I am able to successfully achieve this milestone using following Query:
Create procedure sp_SumSameItems
as
begin
with cte as (select a.Id,a.ItemId,Qty, QtyPrice,
ROW_NUMBER() OVER(PARTITION by ItemId ORDER BY Id) AS rn from tblTest a)
delete x from tblTest x Join cte On x.Id = cte.Id where cte.rn > 1
end
The actual problem is I want to Sum the Qty and QtyPrice before deleting duplicate records. Where should I add Sum function ?
Problem Illustration:
You can't use update with delete statement, you need to update before :
update t
set t.qty = (select sum(t1.qty) from table t1 where t1.itemid = t.itemid);
A CTE is valid for only one statement, so you will need to either run the cte twice, once summing and then deleting or you could put the result of CTE in a temp table and then use the temp table to sum and then delete records in the original table.
At first level, you have to update Qty and QtyPrice after that remove duplicate records.
Given Example:
CREATE PROCEDURE Sp_sumsameitems
AS
BEGIN
WITH cte1
AS (SELECT a.id,
a.itemid,
Sum(qty) Qty,
Sum(qtyprice)QtyPrice,
FROM tbltest a
GROUP BY a.id)
UPDATE x
SET x.qty = c.qty,
x.qtyprice = c.qtyprice
FROM tbltest x
JOIN cte1 c
ON x.id = cte.id
WITH cte
AS (SELECT a.id,
a.itemid,
qty,
qtyprice,
Row_number()
OVER(
partition BY itemid
ORDER BY id) AS rn
FROM tbltest a)
DELETE x
FROM tbltest x
JOIN cte
ON x.id = cte.id
WHERE cte.rn > 1
END
I am trying to group by a column. The problem is that the NULL values of the column are grouped as a separate group.
I want the NULL values to be added to each of the other group values instead.
Example of a table:
The results I want to get from group by with sum aggregation over the 'val' column:
Can anyone help me?
Thanks!
You can precalculate the value to spread through the rows and then just do arithmetic:
select t.id,
sum(t.val) + (null_sum / cnt_id)
from t cross join
(select count(distinct id) as cnt_id,
sum(case when id is null then val else 0 end) as null_sum
from t
) tt
group by t.id;
Note some databases do integer division, so you might need null_sum * 1.0 / cnt_id.
A GROUP BY operation can't really generate values for each group on the fly, so logically you need records which are missing to really be present.
One approach is to use a calendar table to generate a table containing one NULL record for each id group:
WITH ids AS (
SELECT DISTINCT id FROM yourTable
WHERE id IS NOT NULL
),
cte AS (
SELECT t1.id, t2.val
FROM ids t1
CROSS JOIN yourTable t2
WHERE t2.id IS NULL
)
SELECT t.id, SUM(t.val) AS val
FROM
(
SELECT id, val FROM yourTable WHERE id IS NOT NULL
UNION ALL
SELECT id, val FROM cte
) t
GROUP BY
id;
Demo
I have a large table (130 columns). It is a monthly dataset that is separated by month (jan,feb,mar,...). every month I get a small set of duplicate rows. I would like to remove one of the rows, it does not matter which row to be deleted.
This query seems to work ok when I only select the ID that I want to filter the dups on, but when I select everything "*" from the table I end up with all of the rows, dups included. My goal is to filter out the dups and insert the result set into a new table.
SELECT DISTINCT a.[ID]
FROM MonthlyLoan a
JOIN (SELECT COUNT(*) as Count, b.[ID]
FROM MonthlyLoan b
GROUP BY b.[ID])
AS b ON a.[ID] = b.[ID]
WHERE b.Count > 1
and effectiveDate = '01/31/2017'
Any help will be appreciated.
This will show you all duplicates per ID:
;WITH Duplicates AS
(
SELECT ID
rn = ROW_NUMBER() OVER (PARTITION BY ID ORDER BY ID)
FROM MonthlyLoan
)
SELECT ID,
rn
FROM Duplicates
WHERE rn > 1
Alternatively, you can set rn = 2 to find the immediate duplicate per ID.
Since your ID is dupped (A DUPPED ID!!!!)
all you need it to use the HAVING clause in your aggregate.
See the below example.
declare #tableA as table
(
ID int not null
)
insert into #tableA
values
(1),(2),(2),(3),(3),(3),(4),(5)
select ID, COUNT(*) as [Count]
from #tableA
group by ID
having COUNT(*) > 1
Result:
ID Count
----------- -----------
2 2
3 3
To insert the result into a #Temporary Table:
select ID, COUNT(*) as [Count]
into #temp
from #tableA
group by ID
having COUNT(*) > 1
select * from #temp
i have a table similar this
id-value-RowInid
1-xy-1
1-xx-2
1-xz-3
2-xx-1
2-xr-2
3-xq-1
4-xa-1
4-xc-2
...
i need a function for this table with similar output to get maximum of RowInid in separated id group
1-xz-3
2-xr-2
3-xq-1
4-xc-2
...
You just need to use MAX(RowInid) with GROUP BY Id, value
SELECT ID, VALUE, MAX(RowInid) FROM myTable GROUP BY ID, VALUE
EDIT:
As you updated your question, you can get value field using sub-query like this:
SELECT ID, VALUE, RowInid
FROM myTable t1 WHERE RowInid =
(
SELECT MAX(RowInid) FROM myTable WHERE id = t1.id GROUP BY id
)
ORDER BY id ASC;
You can also achieve this using INNER JOIN like this:
SELECT t2.ID, VALUE, t2.RowInid FROM myTable t1
INNER JOIN
(
SELECT ID, MAX(RowInid) AS RowIniD FROM myTable GROUP BY ID
) AS t2
ON t1.ID = t2.ID AND t1.RowInid = t2.RowInid
ORDER BY t1.ID ASC;
See this SQLFiddle
See more about GROUP BY and MAX in SQL Server.
no need for group by or max at all
select id, value, rowinid from
( select *, row_number() over (partition by id, order by rowinid desc) rn from yourtable ) v
where rn = 1
Try with,
Use Sub Query to get Id, Value and Max RowInid,
SELECT m1.[Id],m1.Value, m1.RowInid
FROM [Practice].[dbo].[myTable] m1 WHERE RowInid = (SELECT MAX(m2.RowInid) FROM [Practice].[dbo].[myTable] m2 WHERE M1.Id = m2.Id GROUP BY Id)
above query return result like:
4-xx-2
3-xx-1
2-xx-2
1-xx-3
To Ascending this use,
SELECT m1.[id],m1.Value, m1.RowInid
FROM [Practice].[dbo].[myTable] m1 WHERE m1.RowInid = (SELECT MAX(m2.RowInid) FROM [Practice].[dbo].[myTable] m2 WHERE M2.id = m1.id GROUP BY id) ORDER BY m1.id ASC
I have two columns:
namecode name
050125 chris
050125 tof
050125 tof
050130 chris
050131 tof
I want to group by namecode, and return only the name with the most number of occurrences. In this instance, the result would be
050125 tof
050130 chris
050131 tof
This is with SQL Server 2000
I usually use ROW_NUMBER() to achieve this. Not sure how it performs against various data sets, but we haven't had any performance issues as a result of using ROW_NUMBER.
The PARTITION BY clause specifies which value to "group" the row numbers by, and the ORDER BY clause specifies how the records within each "group" should be sorted. So partition the data set by NameCode, and get all records with a Row Number of 1 (that is, the first record in each partition, ordered by the ORDER BY clause).
SELECT
i.NameCode,
i.Name
FROM
(
SELECT
RowNumber = ROW_NUMBER() OVER (PARTITION BY t.NameCode ORDER BY t.Name),
t.NameCode,
t.Name
FROM
MyTable t
) i
WHERE
i.RowNumber = 1;
select distinct namecode
, (
select top 1 name from
(
select namecode, name, count(*)
from myTable i
where i.namecode = o.namecode
group by namecode, name
order by count(*) desc
) x
) as name
from myTable o
SELECT max_table.namecode, count_table2.name
FROM
(SELECT namecode, MAX(count_name) AS max_count
FROM
(SELECT namecode, name, COUNT(name) AS count_name
FROM mytable
GROUP BY namecode, name) AS count_table1
GROUP BY namecode) AS max_table
INNER JOIN
(SELECT namecode, COUNT(name) AS count_name, name
FROM mytable
GROUP BY namecode, name) count_table2
ON max_table.namecode = count_table2.namecode AND
count_table2.count_name = max_table.max_count
I did not try but this should work,
select top 1 t2.* from (
select namecode, count(*) count from temp
group by namecode) t1 join temp t2 on t1.namecode = t2.namecode
order by t1.count desc
Here are to examples that you could use but the temp table use is more efficient than the view, but was done on a small data sample. You would want to check your own statistics.
--Creating A View
GO
CREATE VIEW StateStoreSales AS
SELECT t.state,t.stor_id,t.stor_name,SUM(s.qty) 'TotalSales'
,ROW_NUMBER() OVER (PARTITION BY t.state ORDER BY SUM(s.qty) DESC) AS 'Rank'
FROM [dbo].[sales] s
JOIN [dbo].[stores] t ON (s.stor_id = t.stor_id)
GROUP BY t.state,t.stor_id,t.stor_name
GO
SELECT * FROM StateStoreSales
WHERE Rank <= 1
ORDER BY TotalSales Desc
DROP VIEW StateStoreSales
---Using a Temp Table
SELECT t.state,t.stor_id,t.stor_name,SUM(s.qty) 'TotalSales'
,ROW_NUMBER() OVER (PARTITION BY t.state ORDER BY SUM(s.qty) DESC) AS 'Rank' INTO #TEMP
FROM [dbo].[sales] s
JOIN [dbo].[stores] t ON (s.stor_id = t.stor_id)
GROUP BY t.state,t.stor_id,t.stor_name
SELECT * FROM #TEMP
WHERE Rank <= 1
ORDER BY TotalSales Desc
DROP TABLE #TEMP