I have a table with 2 columns (id, childId). The data is as follows:
1, 2
3, 4
2, null
4, null
I'm using a CTE so that I get the child records:
DECLARE #id TABLE (id int);
INSERT INTO #id SELECT 1;
INSERT INTO #id SELECT 3;
WITH cte AS
(
SELECT id, childId
FROM mytable
WHERE
id IN (SELECT id FROM #id)
UNION ALL
SELECT b.id, b.childId
FROM mytable b
INNER JOIN cte
ON b.id = cte.childId
)
SELECT * FROM cte
The result always come back as:
1, 2
3, 4
4, null
2, null
But I need the result to look like:
1, 2
2, null
3, 4,
4, null
That is, first the anchor records then the records for the recursive sql for each anchor record.
Is this possible?
Add a static value to in anchor query. Then in recursive part add a static value greater than the static value of anchor query. Now the use static value in Order by
Try this
WITH cte AS
(
SELECT 0 as rn, id, childId
FROM mytable
WHERE
id IN (SELECT id FROM #id)
UNION ALL
SELECT 1 as rn,b.id, b.childId
FROM mytable b
INNER JOIN cte
ON b.id = cte.childId
)
SELECT * FROM cte
Order by rn,id
Also consider adding option(Maxrecursion N). By default it just makes only 100 recursions
By Adding a Seq, the results will be displayed in the proper order/nesting
DECLARE #id TABLE (id int);
INSERT INTO #id SELECT 1;
INSERT INTO #id SELECT 3;
WITH cte AS
(
SELECT id, childId
,Seq = cast(100000+Row_Number() over (Order by id) as varchar(500))
FROM mytable
WHERE
id IN (SELECT id FROM #id)
UNION ALL
SELECT b.id, b.childId
,Seq = cast(concat(cte.Seq,'.',100000+Row_Number() over (Order by b.id)) as varchar(500))
FROM mytable b
INNER JOIN cte
ON b.id = cte.childId
)
SELECT * FROM cte
Order By Seq
Related
I am attempting to randomly join the rows of two tables (TableA and TableB) such that each row in TableA is joined to only one row in TableB and every row in TableB is joined to at least one row in TableA.
For example, a random join of TableA with 5 distinct rows and TableB with 3 distinct rows should result in something like this:
TableA TableB
1 3
2 1
3 1
4 2
5 1
However, sometimes not all the rows from TableB are included in the final result; so in the example above might have row 2 from TableB missing because in its place is either row 1 or 3 joined to row 4 on TableA. You can see this occur by executing the script a number of times and checking the result. It seems that it is necessary for some reason to use an interim table (#Q) to be able to ensure that a correct result is returned which has all rows from both TableA and TableB.
Can someone please explain why this is happening?
Also, can someone please advise on what would be a better way to get the desired result?
I understand that sometimes no result is returned due to a failure of some kind in the cross apply and ordering which i have yet to identify and goes to the point that I am sure there is a better way to perform this operation. I hope that makes sense. Thanks in advance!
declare #TableA table (
ID int
);
declare #TableB table (
ID int
);
declare #Q table (
RN int,
TableAID int,
TableBID int
);
with cte as (
select
1 as ID
union all
select
ID + 1
from cte
where ID < 5
)
insert #TableA (ID)
select ID from cte;
with cte as (
select
1 as ID
union all
select
ID + 1
from cte
where ID < 3
)
insert #TableB (ID)
select ID from cte;
select * from #TableA;
select * from #TableB;
with cte as (
select
row_number() over (partition by TableAID order by newid()) as RN,
TableAID,
TableBID
from (
select
a.ID as TableAID,
b.ID as TableBID
from #TableA as a
cross apply #TableB as b
) as M
)
select --All rows from TableB not always included
TableAID,
TableBID
from cte
where RN in (
select
top 1
iCTE.RN
from cte as iCTE
group by iCTE.RN
having count(distinct iCTE.TableBID) = (
select count(1) from #TableB
)
)
order by TableAID;
with cte as (
select
row_number() over (partition by TableAID order by newid()) as RN,
TableAID,
TableBID
from (
select
a.ID as TableAID,
b.ID as TableBID
from #TableA as a
cross apply #TableB as b
) as M
)
insert #Q
select
RN,
TableAID,
TableBID
from cte;
select * from #Q;
select --All rows from both TableA and TableB included
TableAID,
TableBID
from #Q
where RN in (
select
top 1
iQ.RN
from #Q as iQ
group by iQ.RN
having count(distinct iQ.TableBID) = (
select count(1) from #TableB
)
)
order by TableAID;
See if this gives you what you're looking for...
DECLARE
#CountA INT = (SELECT COUNT(*) FROM #TableA ta),
#CountB INT = (SELECT COUNT(*) FROM #TableB tb),
#MinCount INT;
SELECT #MinCount = CASE WHEN #CountA < #CountB THEN #CountA ELSE #CountB END;
WITH
cte_A1 AS (
SELECT
*,
rn = ROW_NUMBER() OVER (ORDER BY NEWID())
FROM
#TableA ta
),
cte_B1 AS (
SELECT
*,
rn = ROW_NUMBER() OVER (ORDER BY NEWID())
FROM
#TableB tb
),
cte_A2 AS (
SELECT
a1.ID,
rn = CASE WHEN a1.rn > #MinCount THEN a1.rn - #MinCount ELSE a1.rn end
FROM
cte_A1 a1
),
cte_B2 AS (
SELECT
b1.ID,
rn = CASE WHEN b1.rn > #MinCount THEN b1.rn - #MinCount ELSE b1.rn end
FROM
cte_B1 b1
)
SELECT
A = a.ID,
B = b.ID
FROM
cte_A2 a
JOIN cte_B2 b
ON a.rn = b.rn;
I have table described bellow from which I need to select all rows with [Value] greater for example at least 5 points than [Value] from previous row (ordered by [Id]). Starting with first row of [Id] 1, desired output would be:
[Id] [Value]
---------------
1 1
4 12
8 21
Code:
declare #Data table
(
[Id] int not null identity(1, 1) primary key,
[Value] int not null
);
insert into #Data ([Value])
select 1 [Value]
union all
select 5
union all
select 3
union all
select 12
union all
select 8
union all
select 9
union all
select 16
union all
select 21;
select [t1].*
from #Data [t1];
Edit:
So, based on JNevill's and Hogan's answers I end with this:
;with [cte1]
as (
select [t1].[Id],
[t1].[Value],
cast(1 as int) [rank]
from #Data [t1]
where [t1].[Id] = 1
union all
select [t2].[Id],
[t2].[Value],
cast(row_number() over (order by [t2].id) as int) [rank]
FROM [cte1] [t1]
inner join #Data [t2] on [t2].[value] - [t1].[value] > 5
and [t2].[Id] > [t1].[Id]
where [t1].[rank] = 1
)
select [t1].[Id],
[t1].[Value]
from [cte1] [t1]
where [t1].[rank] = 1;
which is working. Alan Burstein answer is correct too (but applicable only on MSSQL 2012+ - due to LAG fc). I will do some performance tests (I'm on 2016 version) and will see performance over my real data (approx. 30 millions of records).
If you are on 2012+ you can use LAG which will provide a better performing solution that a recursive CTE. I'm including your sample data so you can just copy/paste/test...
-- Your sample data
DECLARE #Data TABLE
(
Id int not null identity(1, 1) primary key,
Value int not null
);
insert into #Data ([Value])
select 1 [Value] union all select 5 union all select 3 union all select 12 union all
select 8 union all select 9 union all select 16 union all select 21;
-- Solution using window functions
WITH
prevRows AS
(
SELECT t1.Id, t1.Value, prevDiff = LAG(t1.Value, 1) OVER (ORDER BY t1.id) - t1.Value
FROM #Data t1
),
NewPrev AS
(
SELECT t1.Id, t1.Value, NewDiff = Value - LAG(t1.Value,1) OVER (ORDER BY t1.id)
FROM prevRows t1
WHERE prevDiff <= -5 OR prevDiff IS NULL
)
SELECT t1.Id, t1.Value
FROM NewPrev t1
WHERE NewDiff >= 5 OR NewDiff IS NULL;
I believe the best way to pull this off is using a recursive CTE. A Recursive CTE is a special type of CTE that refers back to itself. It's made up of two parts.
The recursive seed/anchor which establishes the beginning of the recursion. In your case, record with ID=1.
The recursive term/member which is the statement that refers back to itself by the name of the CTE. Here we pull through the next record that is greater than 5 from the previous found record according to the ID sorted ascending.
Code:
WITH RECURSIVE recCTE AS
(
/*Select first record for recursive seed/anchor*/
SELECT
id,
value,
cast(1 as INT) as [rank]
FROM table
WHERE id = 1
UNION ALL
/*find the next value that is more than 5 from the current value*/
SELECT
table.id,
table.value
ROW_NUMBER() OVER (ORDER BY id)
FROM
recCTE INNER JOIN table
ON table.value - recCTE.value > 5
AND table.id > recCTE.id
WHERE recCTE.[rank]=1
)
SELECT id, value FROM recCTE;
I've made use of the Row_Number() Window Function to find the rank of the matching record by ID sorted Ascending. With the WHERE clause in the recursive term we only grab the first found record that is 5 more than the previous found record. Then we head into the next recursive step.
You can do it with a recursive CTE
with find_values as
(
-- Find first value
SELECT Value
FROM #Table
ORDER BY ID ASC
FETCH FIRST 1 ROW ONLY
UNION ALL
-- Find next value
SELECT Value
FROM #Table
CROSS JOIN find_values
WHERE Value >= find_values.Value + 5
ORDER BY ID ASC
FETCH FIRST 1 ROW ONLY
)
SELECT *
FROM find_values
I have to change RowSpan value if OccupationalInjuryId's duplicate value exists. Here is the screenshot:
Should I use T-SQL or #temporary table structure. But I couldn't figure out how to fix. For example there are two values with OccupationalId = 1100 and both rowspan's are 2. It should be 1 for second value's RowSpan no.
My SQL query:
select *
from
(select
Row_Number() over (order by oi.Id) as RowNo,
oid.OccupationalInjuryId
from
OTH_OccupationalInjury oi
left join
OTH_OccupationalInjuryDetail oid on oi.Id = oid.OccupationalInjuryId
where
1 = 1) t1
left join
(select
count(OccupationalInjuryId) end as RowSpan,
oid.OccupationalInjuryId
from
OTH_OccupationalInjury oi
left join
OTH_OccupationalInjuryDetail oid on oi.Id = oid.OccupationalInjuryId
where
1=1
group by
OccupationalInjuryId
having
(Count(OccupationalInjuryId) > 1) ) t2 on t1.OccupationalInjuryId = t2.OccupationalInjuryId
END
If I got you correctly, you only care about first RowSpan value for each OccupationalInjuryId and for others you want 1. If I am wrong, correct me.
So, Can you try something like :
DECLARE #BaseTable TABLE(ID INT, OccupationalInjuryId INT, RowSpan INT)
INSERT INTO #BaseTable (ID, OccupationalInjuryId, RowSpan)
SELECT 1, 1100, 2 UNION ALL
SELECT 2, 1100, 2 UNION ALL
SELECT 3, 1099, 2 UNION ALL
SELECT 4, 1099, 3 UNION ALL
SELECT 5, 1106, NULL
SELECT
ID,
OccupationalInjuryId,
CASE WHEN rn = 1 THEN RowSpan ELSE 1 END AS RowSpan
FROM
(
SELECT ID, OccupationalInjuryId, RowSpan, ROW_NUMBER() OVER (PARTITION BY OccupationalInjuryId, RowSpan ORDER BY ID) AS rn FROM #BaseTable
) tmp
I have a two tables like below
A
Id Name
1 a
2 b
B
Id Name
1 t
6 s
My requirement is to find the maximum id from table and display the name and id for that maximum without using case and if.
i findout the maximum by using below query
SELECT MAX(id)
FROM (SELECT id,name FROM A
UNION
SELECT id,name FROM B) as c
I findout the maximum 6 using the above query.but i can't able to find the name.I tried the below query but it's not working
SELECT MAX(id)
FROM (SELECT id,name FROM A
UNION
SELECT id,name FROM B) as c
How to find the name?
Any help will be greatly appreciated!!!
First combine the tables, since you need to search both. Next, determine the id you need. JOIN the id back with the temporarily created table to retreive the name that belongs to that id:
WITH tmpTable AS (
SELECT id,name FROM A
UNION
SELECT id,name FROM B
)
, max AS (
SELECT MAX(id) id
FROM tmpTable
)
SELECT t.id, t.name
FROM max m
JOIN tmpTable t ON m.id = t.id
You could use ROW_NUMBER(). You have to UNION ALL TableA and TableB first.
WITH TableA(Id, Name) AS(
SELECT 1, 'a' UNION ALL
SELECT 2, 'b'
)
,TableB(Id, Name) AS(
SELECT 1, 't' UNION ALL
SELECT 6, 's'
)
,Combined(Id, Name) AS(
SELECT * FROM TableA UNION ALL
SELECT * FROM TableB
)
,CTE AS(
SELECT *, RN = ROW_NUMBER() OVER(ORDER BY ID DESC) FROM Combined
)
SELECT Id, Name
FROM CTE
WHERE RN = 1
Just order by over the union and take first row:
SELECT TOP 1 * FROM (SELECT * FROM A UNION SELECT * FROM B) x
ORDER BY ID DESC
This won't show ties though.
For you stated that you used SQL Server 2008. Therefore,I used FULL JOIN and NESTED SELECT to get what your looking for. See below:
SELECT
(SELECT
1,
ISNULL(A.Id,B.Id)Id
FROM A FULL JOIN B ON A.Id=B.Id) AS Id,
(SELECT
1,
ISNULL(A.Name,B.Name)Name
FROM A FULL JOIN B ON A.Id=B.Id) AS Name
It's possible to use ROW_NUMBER() or DENSE_RANK() functions to get new numiration by Id, and then select value with newly created orderId equal to 1
Use:
ROW_NUMBER() to get only one value (even if there are some repetitions of max id)
DENSE_RANK() to get all equal max id values
Here is an example:
DECLARE #tb1 AS TABLE
(
Id INT
,[Name] NVARCHAR(255)
)
DECLARE #tb2 AS TABLE
(
Id INT
,[Name] NVARCHAR(255)
)
INSERT INTO #tb1 VALUES (1, 'A');
INSERT INTO #tb1 VALUES (7, 'B');
INSERT INTO #tb2 VALUES (4, 'C');
INSERT INTO #tb1 VALUES (7, 'D');
SELECT * FROM
(SELECT Id, Name, ROW_NUMBER() OVER (ORDER BY Id DESC) AS [orderId]
FROM
(SELECT Id, Name FROM #tb1
UNION
SELECT Id, Name FROM #tb2) as tb3) AS TB
WHERE [orderId] = 1
SELECT * FROM
(SELECT Id, Name, DENSE_RANK() OVER (ORDER BY Id DESC) AS [orderId]
FROM
(SELECT Id, Name FROM #tb1
UNION
SELECT Id, Name FROM #tb2) as tb3) AS TB
WHERE [orderId] = 1
Results are:
I have a table with a recursive hierarchy (i.e. ID, ParentID). For any item in this hierachy, I want to be able to bring back a list of everything UP AND DOWN the hierarchy along with the level for each row. Assume that a parent can only ever have a single child.
Take for example the following:
ID ParentID
--------------
1 NULL
2 1
3 2
4 NULL
5 4
6 5
Given ID 1, 2, or 3, I want to return:
ID ParentID Level
-----------------------
1 NULL 1
2 1 2
3 2 3
I've done this before, but I can't remember how. I know the solution involves a CTE, I just can't get it right! Any help is appreciated.
;with cte as
(
select *, 1 as level from #t where id = #yourid
union all
select t.*, level - 1
from cte
inner join #t t on cte.parent = t.id
),
cte2 as
(
select * from cte
union all
select t.*, level+1
from cte2
inner join #t t on cte2.id = t.parent
)
select id,parent, ROW_NUMBER() over (order by level) level
from ( select distinct id, parent, level from cte2) v
The most barebones version of the CTE query I could come up with is:
WITH Ancestry (AncestorID, DescendantID)
AS
(
SELECT
ParentID, ID
FROM
dbo.Location
WHERE
ParentID IS NOT NULL
UNION ALL
SELECT
P.AncestorID, C.ID
FROM
dbo.Location C
JOIN
Ancestry P on C.ParentID = P.DescendantID
)
SELECT * FROM Ancestry
The result is a list of all Ancestor/Descendant relationships that exist in the table.
The final "SELECT * FROM Ancestry" can be replaced with something more complex to filter, order, etc.
To include reflexive relationships, the query can be modified by adding two lines to the final SELECT statement:
SELECT * FROM Ancestry
UNION
SELECT ID, ID FROM dbo.Location
;WITH Recursive_CTE AS (
SELECT
child.ExecutiveId,
CAST(child.ExecutiveName as varchar(100)) BusinessUnit,
CAST(NULL as bigint) ParentUnitID,
CAST(NULL as varchar(100)) ParentUnit,
CAST('' as varchar(100)) LVL,
CAST(child.ExecutiveId as varchar(100)) Hierarchy,
1 AS RecursionLevel
FROM Sales_Executive_level child
WHERE ExecutiveId = 4000 --your Id which you want to get all parent node
UNION ALL
SELECT
child.ExecutiveId,
CAST(LVL + child.ExecutiveName as varchar(100)) AS BusinessUnit,
child.ParentExecutiveID,
parent.BusinessUnit ParentUnit,
CAST('' + LVL as varchar(100)) AS LVL,
CAST(Hierarchy + ':' + CAST(child.ExecutiveId as varchar(100)) as varchar(100)) Hierarchy,
RecursionLevel + 1 AS RecursionLevel
FROM Recursive_CTE parent
INNER JOIN Sales_Executive_level child ON child.ParentExecutiveID = parent.ExecutiveId
)
SELECT * FROM Recursive_CTE ORDER BY Hierarchy
OPTION (MAXRECURSION 300);