Getting the greater of two values in SQL - sql-server

I have a SQL Server table. This table has two tables: Order and OrderInProgress. These two tables have similar structures:
Order[InProgress]
-----------------
ID (uniqueidentifier)
CreateDate
...
I need to get the latest Order or OrderInProgress
DECLARE #latestOrderID uniqueidentifier
#latestOrderID = ?
How do I set #latestOrderID to the most recent Order or OrderInProgress ID? I can't figure out how to do this in SQL.
Thank you!

Try this, which should be more efficient whenever it matters.
select top 1 ID from (
select top 1 ID from Order order by ID desc
union all
select top 1 ID from OrderInProgress order by ID desc
) T
order by ID desc

Have you tried:
SELECT TOP 1 #latestOrderID = ID FROM [Order] ORDER BY CreateDate DESC

SELECT * FROM
(SELECT 'Order' tablename, max(ID) max_id FROM Order
UNION
SELECT 'OrderInProgress' tablename, max(ID) max_id FROM OrderInProgress
) maxes ORDER BY max_id DESC

Related

tsq - take the highest int in duplicate row

I have the following rows in a table
name, tagid
-------
test1,1
test1,100
test2,2
test2,200
test3,3
test3,300
There are duplicates in the name.
Is there a way to select unique names by taking the highest tagid of each group?
select name,max(tagid) as highest_tagid
from tbl
group by name
;WITH cte AS
(
SELECT *, ROW_NUMBER() OVER (PARTITION BY name ORDER BY tagid DESC) AS rn
FROM table_1
)
SELECT *
FROM cte
WHERE rn = 1

SQL Server: How to select fist 10 records from table without using TOP keyword

There is a table which contains 50 records. I want to select first 10 records without using TOP keyword.
In SQL Server 2012+ you can use OFFSET ... FETCH
SELECT *
FROM YourTable
ORDER BY YourColumn ASC
OFFSET 0 ROWS
FETCH FIRST 10 ROWS ONLY
You can use ROW_NUMBER and Common Table Expression to query any range of data.
USE AdventureWorks2012;
GO
WITH OrderedOrders AS
(
SELECT SalesOrderID, OrderDate,
ROW_NUMBER() OVER (ORDER BY OrderDate) AS RowNumber
FROM Sales.SalesOrderHeader
)
SELECT SalesOrderID, OrderDate, RowNumber
FROM OrderedOrders
WHERE RowNumber <= 10 -- other conditions: RowNumber between 50 and 60
Refere ROW NUMBER Here
Although it's probably the same thing internally, you can use
set rowcount 10
and then run the query.
I guess you can try something like this:
SELECT t.Id, t.Name FROM Table t
WHERE 10 > (SELECT count(*) FROM Table t2 WHERE t.id > t2.id)
You can use ROW_NUMBER. Let's say your table contains columns ID and Name. In that case you can use such query:
SELECT t.Id, t.Name
FROM (
SELECT ID, Name,
ROW_NUMBER() OVER (ORDER BY Id) AS RowNumber
FROM TableName
) t
WHERE RowNumber <= 10

using subquery in between operator

hie all,
my query is this
select * from [order] where createdon<getdate()-7
and orderid between
(select top 1 orderid from [order] where createdon<getdate()-7 order by orderid) as oId
and oId+100 order by orderid
It is giving error. please tell me where is it going wrong
my intention is to get 100 orders from order table which are older than 7 days. and please dont suggest fetching it using row_number
Thanks
You can't alias expressions in the WHERE clause. But since your subquery returns just one row, you could cross join it to the [order] table and filter on the returned top orderid value like this:
SELECT [order].*
FROM [order]
CROSS JOIN (
SELECT TOP 1 orderid
FROM [order]
WHERE createdon < GETDATE() - 7
ORDER BY orderid
) toporder
WHERE [order].createdon < GETDATE() - 7
AND [order].orderid BETWEEN toporder.orderid AND toporder.orderid + 100
select * from
(
select top 100 * from [order] where
createdon<dateadd(day, -7, getdate())
order by orderid desc
)
order by orderid asc
Assume you use MSSQL, use TOP keyword to limit output :
SELECT TOP 100 ...

SQL SERVER : select the latest comment using the max date

I have a table like so:
Id, Comment, LastUpdatedDate
I'm tyring to select the latest comment for that id. The table can have many comments on that id with different dates but I'm trying to get the latest date out of there. I've tried the following with no success:
SELECT tt.*
FROM tagtestresultcomment tt
INNER JOIN
(
SELECT tag_id, MAX(last_update) AS MaxDateTime
FROM tagtestresultcomment
GROUP BY tag_id
) groupedtt ON tt.tag_id = groupedtt.tag_id AND tt.last_update = groupedtt.MaxDateTime
order by tag_id
Does anyone have any ideas of how to achieve this?
Thanks!
It sounds like you want only the latest comment for each tag_id? In which case, here is one approach you can use from SQL 2005 and on:
;WITH CTE AS
(
SELECT *,
ROW_NUMBER() OVER(PARTITION BY tag_id ORDER BY last_update DESC) AS RowNo
FROM TagTestResultComment
)
SELECT * FROM CTE WHERE RowNo = 1
try this
Select * from tagtestresultcomment where last_update in
(select max(last_update) from tagtestresultcomment group by tag_id)
your query code is too redundant. first
tt.tag_id = groupedtt.tag_id AND tt.last_update = groupedtt.MaxDateTime
it's enough just
tt.tag_id = groupedtt.tag_id
and second, it's enough just
SELECT [desired field list extcept last_update and ],
tag_id,
MAX(last_update) AS MaxDateTime
FROM
tagtestresultcomment
group by
tag_id, [desired field list extcept last_update and tag_id]
at all to achieve your objective
I have tried something like this:
declare #tagtestresultcomment table
(
id int
, comment varchar(50)
,LastUpdatedDate datetime
)
--==== Populate table
insert into #tagtestresultcomment(id,comment,LastUpdatedDate)
select 1,'My name is Arthur','2011-06-09 00:00:00' union all
select 2,'My name is DW','2011-06-19 00:00:00' union all
select 2,'Arthur is my brother','2011-06-21 00:00:00' union all
select 1,'I have a sister named DW','2011-06-21 00:00:00' union all
select 3,'I am Muffy','2011-06-14 00:00:00' union all
select 3,'I like sports','2011-06-14 00:00:00'
-- SELECT stmt
select * from #tagtestresultcomment t
join
(
select id, MAX(lastupdateddate) as LastUpdatedDate from #tagtestresultcomment group by id
) m
on t.id = m.id
and t.LastUpdatedDate = m.LastUpdatedDate
The "MAX" group function wasn't working for me, so I used a sub-query. I had trouble wrapping my head around your single table example, so I'm using a common parent-child 1-to-many relationship with a blog and comment tables as an example.
SELECT
b.id,
b.content,
c.id,
c.blog_id,
c.content,
c.last_update
FROM blog b
INNER JOIN blog_comment c
ON b.id = c.blog_id AND c.id = (
SELECT TOP 1 id FROM blog_comment WHERE blog_id = b.id ORDER BY last_update DESC
)
The query takes a hit on my sub-query, as it will call that "SELECT TOP 1" query for each record in the blog table. I'd like to hear of a faster, more efficient example if possible.

select top 1 with a group by

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

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