I'm trying to select rows one by one in a while loop in SQL Server. And I'm using the only way I know to select the next row using ROW_NUMBER function. But I also have to assign values to t-sql variables in the same SELECT statement thus I'm getting the following error;
A SELECT statement that assigns a value to a variable must not
be combined with data-retrieval operations.
Anyway my code is like this;
WHILE (#i < 5)
BEGIN
SELECT -- This is where the error occurs
#resultId = video.id, -- this is the value assigning i need to do
ROW_NUMBER() OVER (ORDER BY dateAdded DESC) AS ROWID
FROM videoTest.dbo.video
LEFT JOIN videoTest.dbo.aspnet_Users
ON video.userId=aspnet_Users.UserId
WHERE aspnet_Users.UserName=#searchUserName AND ROWID = #i
-- Processing #resultId
SELECT
compilationId
FROM videoTest.dbo.comp
WHERE vidId = #resultId -- i need the id from above
....
....
.....
......
#i = #i + 1
END
I would be much appreciated if you can show me way to select next in an alternative way without getting this error, or a way to solve this error in my current code.
Thanks.
You need to separate out the selection of the data from the retrieval of that data into a variable. You could use e.g. a CTE (Common Table Expression) to set up the data, and then operate on that data. However, on a more basic level : why are you assigning the id to #resultId five times?? You don't seem to be doing anything with the #resultId in the meantime.....
Could you change your logic to be more set-based ? Instead of a WHILE construct - just select the appropriate values from the CTE:
;WITH VideoData AS
(
SELECT
video.id,
ROW_NUMBER() OVER (ORDER BY dateAdded DESC) AS ROWID
FROM
videoTest.dbo.video
LEFT JOIN
videoTest.dbo.aspnet_Users ON video.userId = aspnet_Users.UserId
WHERE
aspnet_Users.UserName = #searchUserName
)
SELECT id, ROWID
FROM VideoData
WHERE ROWID <= 5
Update: if you need the five video.id values for later processing, try something like this:
DECLARE #VideoIDs TABLE (VideoID INT)
;WITH VideoData AS
(
... (same as before)
)
INSERT INTO #VideoIDs(VideoID)
SELECT id
FROM VideoData
WHERE ROWID <= 5
-- use your values in the table variable here.....
I see that you need video.id. Why not just order by dateAdded, and store it in a cursor:
SELECT
INTO CURSOR #SomeCursor
video.id
FROM videoTest.dbo.video
LEFT JOIN videoTest.dbo.aspnet_Users
ON video.userId=aspnet_Users.UserId
WHERE aspnet_Users.UserName=#searchUserName
ORDER BY dateAdded DESC
and then iterate #SomeCursor?
Related
I'm loading some quite nasty data through Azure data factory
This is how the data looks after being loaded, existing of 2 parts:
1. Metadata of a test
2. Actual measurements of the test -> the measurement is numeric
Image I have about 10 times such 'packages' of 1.Metadata + 2.Measurements
What I would like it to be / what I'm looking for is the following:
The number column with 1,2,.... is what I'm looking for!
Imagine my screenshot could go no further but this goes along until id=10
I guess a while loop is necessary here...
Query before:
SELECT Field1 FROM Input
Query after:
SELECT GeneratedId, Field1 FROM Input
Thanks a lot in advance!
EDIT: added a hint:
Here is a solution, this requires SQL-SERVER 2012 or later.
Start by getting an Id column on your data. If you can do this previous to the script that would be even better, but if not, try something like this...
CREATE TABLE #InputTable (
Id INT IDENTITY(1, 1),
TestData NVARCHAR(MAX) )
INSERT INTO #InputTable (TestData)
SELECT Field1 FROM Input
Now create a query to get the GeneratedId of each package as well as the Id where they start and end. You can do this by getting all the records LIKE 'title%' since that is the first record of each package, then using ROW_NUMBER, Id, and LEAD for the GeneratedId, StartId, and EndId respectively.
SELECT
GeneratedId = ROW_NUMBER() OVER(ORDER BY (Id)),
StartId = Id,
EndId = LEAD(Id) OVER (ORDER BY (Id))
FROM #InputTable
WHERE TestData LIKE 'title%'
Lastly, join this to the input in order to get all the records, with the correct GeneratedId.
SELECT
package.GeneratedId, i.TestData
FROM (
SELECT
GeneratedId = ROW_NUMBER() OVER(ORDER BY (Id)),
StartId = Id,
EndId = LEAD(Id) OVER (ORDER BY (Id))
FROM #InputTable
WHERE TestData LIKE 'title%' ) package
INNER JOIN #InputTable i
ON i.Id >= package.StartId
AND (package.EndId IS NULL OR i.Id < package.EndId)
I wonder if the following a bit contrived example is possible without using intermediary variables and a conditional clause.
Consider an intermediary query which can produce a result set that contain either no rows, one row or multiple rows. Most of the time it produces just one row, but when multiple rows, one should join the resulting rows to another table to prune it down to either one or no rows. After this if there is one row (as opposed to no rows), one would want to return multiple columns as produced by the original intermediary query.
I have in my mind something like following, but it won't obviously work (multiple columns in switch-case, no join etc.), but maybe it illustrates the point. What I would like to have is to just return what is currently in the SELECT clause in case ##ROWCOUNT = 1 or in case it is greater, do a INNER JOIN to Auxilliary, which prunes down x to either one row or no rows and then return that. I don't want to search Main more than once and Auxilliary only when x here contains more than one row.
SELECT x.MainId, x.Data1, x.Data2, x.Data3,
CASE
WHEN ##ROWCOUNT IS NOT NULL AND ##ROWCOUNT = 1 THEN
1
WHEN ##ROWCOUNT IS NOT NULL AND ##ROWCOUNT > 1 THEN
-- Use here #id or MainId to join to Auxilliary and there
-- FilteringCondition = #filteringCondition to prune x to either
-- one or zero rows.
END
FROM
(
SELECT
MainId,
Data1,
Data2,
Data3
FROM Main
WHERE
MainId = #id
) AS x;
CREATE TABLE Main
(
-- This Id may introduce more than row, so it is joined to
-- Auxilliary for further pruning with the given conditions.
MainId INT,
Data1 NVARCHAR(MAX) NOT NULL,
Data2 NVARCHAR(MAX) NOT NULL,
Data3 NVARCHAR(MAX) NOT NULL,
AuxilliaryId INT NOT NULL
);
CREATE TABLE Auxilliary
(
AuxilliaryId INT IDENTITY(1, 1) PRIMARY KEY,
FilteringCondition NVARCHAR(1000) NOT NULL
);
Would this be possible in one query without a temporary table variable and a conditional? Without using a CTE?
Some sample data would be
INSERT INTO Auxilliary(FilteringCondition)
VALUES
(N'SomeFilteringCondition1'),
(N'SomeFilteringCondition2'),
(N'SomeFilteringCondition3');
INSERT INTO Main(MainId, Data1, Data2, Data3, AuxilliaryId)
VALUES
(1, N'SomeMainData11', N'SomeMainData12', N'SomeMainData13', 1),
(1, N'SomeMainData21', N'SomeMainData22', N'SomeMainData23', 2),
(2, N'SomeMainData31', N'SomeMainData32', N'SomeMainData33', 3);
And a sample query, which actually behaves as I'd like it to behave with the caveat I'd want to do the join only if querying Main directly with the given ID produces more than one result.
DECLARE #id AS INT = 1;
DECLARE #filteringCondition AS NVARCHAR(1000) = N'SomeFilteringCondition1';
SELECT *
FROM
Main
INNER JOIN Auxilliary AS aux ON aux.AuxilliaryId = Main.AuxilliaryId
WHERE MainId = #id AND aux.FilteringCondition = #filteringCondition;
You don't usually use a join to reduce the result set of the left table. To limit a result set you'd use the where clause instead. In combination with another table this would be WHERE [NOT] EXISTS.
So let's say this is your main query:
select * from main where main.col1 = 1;
It returns one of the following results:
no rows, then we are done
one row, then we are also done
more than one row, then we must extend the where clause
The query with the extended where clause:
select * from main where main.col1 = 1
and exists (select * from other where other.col2 = main.col3);
which returns one of the following results:
no rows, which is okay
one row, which is okay
more than one row - you say this is not possible
So the task is to do this in one step instead. I count records and look for a match in the other table for every record. Then ...
if the count is zero we get no result anyway
if it is one I take that row
if it is greater than one, I take the row for which exists a match in the other table or none when there is no match
Here is the full query:
select *
from
(
select
main.*,
count(*) over () as cnt,
case when exists (select * from other where other.col2 = main.col3) then 1 else 0 end
as other_exists
from main
where main.col1 = 1
) counted_and_checked
where cnt = 1 or other_exists = 1;
UPDATE: I understand that you want to avoid unnecessary access to the other table. This is rather difficult to do however.
In order to only use the subquery when necessary, we could move it outside:
select *
from
(
select
main.*,
count(*) over () as cnt
from main
where main.col1 = 1
) counted_and_checked
where cnt = 1 or exists (select * from other where other.col2 = main.col3);
This looks much better in my opinion. However there is no precedence among the two expressions left and right of an OR. So the DBMS may still execute the subselect on every record before evaluating cnt = 1.
The only operation that I know of using left to right precedence, i.e. doesn't look further once a condition on the left hand side is matched is COALESCE. So we could do the following:
select *
from
(
select
main.*,
count(*) over () as cnt
from main
where main.col1 = 1
) counted_and_checked
where coalesce( case when cnt = 1 then 1 else null end ,
(select count(*) from other where other.col2 = main.col3)
) > 0;
This may look a bit strange, but should prevent the subquery from being executed, when cnt is 1.
You may try something like
select * from Main m
where mainId=#id
and #filteringCondition = case when(select count(*) from Main m2 where m2.mainId=#id) >1
then (select filteringCondition from Auxilliary a where a.AuxilliaryId = m.AuxilliaryId) else #filteringCondition end
but it's hardly very fast query. I'd better use temp table or just if and two queries.
I have a table say MyTable has two columns Id, Data and has following records in it:
Id Data
----------
1. ABCDE00
2. DEFGH11
3. CCCCC21
4. AAAAA00
5. BBBBB10
6. vvvvv00
7. xxxxx88
Now what I want that all the records which have end with string 00 and does not have subsequent row having column ending with 11.
So my output using this condition should be like this:
1. AAAAA00
2. vvvvv00
Any help would be appreciated.
This answer makes some assumptions:
You have a column specifying the ordering. Let me call it id.
By "subsequent row" you mean the row with the next highest id.
You are using SQL Server 2012+.
In that case, lead() does what you want:
select t.*
from (select t.*, lead(data order by id) as next_data
from t
) t
where data like '%00' and (next_data not like '%11' or next_data is null);
Earlier versions of SQL Server have alternative methods for calculating next_data.
if anyone is not using sql server 2012,then they an try this
declare #t table(id int identity(1,1),col1 varchar(100))
insert into #t values
('ABCDE00')
,('DEFGH11')
,('CCCCC21')
,('AAAAA00')
,('BBBBB10')
,('vvvvv00')
,('xxxxx88')
;With CTE as
(
select *,case when CHARINDEX('00',reverse(col1))>0 then 1 end
End00 from #t
)
,CTE1 as
(
select a.id,a.col1 from cte A
where exists
(select id from cte b where a.id=b.id+1 and b.end00 is not null)
and CHARINDEX('11',reverse(a.col1))<=0
)
select a.id,a.col1 from cte A
where exists
(select id from cte1 b where a.id=b.id-1 )
I am testing out moving our database from SQL Server 2005 to 2008. We use CTE's for paging.
When using full-text CONTAINSTABLE, the CTE will not run and generates an error.
Here's my non-working code-
WITH results AS (
SELECT ROW_NUMBER() over (ORDER BY GBU.CreateDate DESC ) as rowNum,
GBU.UserID,
NULL AS DistanceInMiles
FROM User GBU WITH (NOLOCK)
WHERE 1=1
AND GBU.CountryCode IN (SELECT [Value] FROM fn_Split('USA',','))
AND GBU.UserID IN (SELECT [KEY] FROM CONTAINSTABLE(VW_GBU_Search, *, 'COMPASS'))
)
SELECT * from results
WHERE rowNum BETWEEN 0 and 25
If I comment out the CONTAINSTABLE line, the statement executes. If I only run the SELECT statement (not the WITH), the statement executes fine.
The un-helpful error I get on this is:
Msg 0, Level 11, State 0, Line 0 A
severe error occurred on the current
command. The results, if any, should
be discarded. Msg 0, Level 20, State
0, Line 0 A severe error occurred on
the current command. The results, if
any, should be discarded.
Any suggestions?
Appears to be a bug. See http://connect.microsoft.com/SQLServer/feedback/ViewFeedback.aspx?FeedbackID=426981
Sounds like the fix should be in the next MSSQL SP.
Assuming the other answers are correct, and that the underlying issue is a bug, since you aren't referencing RANK from CONTAINSTABLE, perhaps a query something like the following would be a workaround, where "ID" is the ID column in VW_GBU_Search (untested)?
;WITH results AS (
SELECT ROW_NUMBER() OVER (ORDER BY GBU.CreateDate DESC ) AS rowNum,
GBU.UserID,
NULL AS DistanceInMiles
FROM User GBU WITH (NOLOCK)
WHERE 1=1
AND GBU.CountryCode IN (SELECT [Value] FROM fn_Split('USA',','))
AND GBU.UserID IN (SELECT ID FROM VW_GBU_Search WHERE CONTAINS(*, 'COMPASS'))
)
SELECT * FROM results
WHERE rowNum BETWEEN 0 AND 25
Also, why do you have the "1=1" clause? Can you eliminate it?
I banged my head against the wall on this problem for hours; here is a workaround:
ASSUME: A table in database called
Items ( ItemId int PK, Content varchar(MAX) ),
which has a fulltext index already applied.
GO
CREATE FUNCTION udf_SearchItemsTable(#FreeText)
RETURNS #SearchHits
TABLE(
Relevance int,
ItemId int,
Content varchar(MAX)
)
AS
BEGIN
INSERT #SearchHits
SELECT Results.[Rank] AS Relevance
,Items.ItemId AS ItemId
,Items.Content AS Content
FROM SearchableItems AS Items INNER JOIN
CONTAINSTABLE(SearchableItems, *, #FreeText) AS Results
Results.[Key] = Items.Id
RETURN
END
GO
...
GO
CREATE FUNCTION udf_SearchItems( #SearchText, #StartRowNum, #MaxRows)
RETURNS #SortedItems
TABLE (
ItemId int,
Content varchar(MAX)
)
AS
BEGIN
WITH Matches AS
(
SELECT
ROW_NUMBER() OVER (ORDER BY Hits.Relevance DESC) AS RowNum
,Hits.*
FROM ( udf_SearchItemsTable(#SearchText) ) AS Hits
)
SELECT
ItemId, Content
FROM
Matches
WHERE
Matches.RowNum BETWEEN #StartRowNum
AND #StartRowNum + #MaxRows
;
RETURN
END
GO
select * from udf_SearchItems('some free text stuff', 10, 20)
I've got a standard boss/subordinate employee table. I need to select a boss (specified by ID) and all his subordinates (and their subrodinates, etc). Unfortunately the real world data has some loops in it (for example, both company owners have each other set as their boss). The simple recursive query with a CTE chokes on this (maximum recursion level of 100 exceeded). Can the employees still be selected? I care not of the order in which they are selected, just that each of them is selected once.
Added: You want my query? Umm... OK... I though it is pretty obvious, but - here it is:
with
UserTbl as -- Selects an employee and his subordinates.
(
select a.[User_ID], a.[Manager_ID] from [User] a WHERE [User_ID] = #UserID
union all
select a.[User_ID], a.[Manager_ID] from [User] a join UserTbl b on (a.[Manager_ID]=b.[User_ID])
)
select * from UserTbl
Added 2: Oh, in case it wasn't clear - this is a production system and I have to do a little upgrade (basically add a sort of report). Thus, I'd prefer not to modify the data if it can be avoided.
I know it has been a while but thought I should share my experience as I tried every single solution and here is a summary of my findings (an maybe this post?):
Adding a column with the current path did work but had a performance hit so not an option for me.
I could not find a way to do it using CTE.
I wrote a recursive SQL function which adds employeeIds to a table. To get around the circular referencing, there is a check to make sure no duplicate IDs are added to the table. The performance was average but was not desirable.
Having done all of that, I came up with the idea of dumping the whole subset of [eligible] employees to code (C#) and filter them there using a recursive method. Then I wrote the filtered list of employees to a datatable and export it to my stored procedure as a temp table. To my disbelief, this proved to be the fastest and most flexible method for both small and relatively large tables (I tried tables of up to 35,000 rows).
this will work for the initial recursive link, but might not work for longer links
DECLARE #Table TABLE(
ID INT,
PARENTID INT
)
INSERT INTO #Table (ID,PARENTID) SELECT 1, 2
INSERT INTO #Table (ID,PARENTID) SELECT 2, 1
INSERT INTO #Table (ID,PARENTID) SELECT 3, 1
INSERT INTO #Table (ID,PARENTID) SELECT 4, 3
INSERT INTO #Table (ID,PARENTID) SELECT 5, 2
SELECT * FROM #Table
DECLARE #ID INT
SELECT #ID = 1
;WITH boss (ID,PARENTID) AS (
SELECT ID,
PARENTID
FROM #Table
WHERE PARENTID = #ID
),
bossChild (ID,PARENTID) AS (
SELECT ID,
PARENTID
FROM boss
UNION ALL
SELECT t.ID,
t.PARENTID
FROM #Table t INNER JOIN
bossChild b ON t.PARENTID = b.ID
WHERE t.ID NOT IN (SELECT PARENTID FROM boss)
)
SELECT *
FROM bossChild
OPTION (MAXRECURSION 0)
what i would recomend is to use a while loop, and only insert links into temp table if the id does not already exist, thus removing endless loops.
Not a generic solution, but might work for your case: in your select query modify this:
select a.[User_ID], a.[Manager_ID] from [User] a join UserTbl b on (a.[Manager_ID]=b.[User_ID])
to become:
select a.[User_ID], a.[Manager_ID] from [User] a join UserTbl b on (a.[Manager_ID]=b.[User_ID])
and a.[User_ID] <> #UserID
You don't have to do it recursively. It can be done in a WHILE loop. I guarantee it will be quicker: well it has been for me every time I've done timings on the two techniques. This sounds inefficient but it isn't since the number of loops is the recursion level. At each iteration you can check for looping and correct where it happens. You can also put a constraint on the temporary table to fire an error if looping occurs, though you seem to prefer something that deals with looping more elegantly. You can also trigger an error when the while loop iterates over a certain number of levels (to catch an undetected loop? - oh boy, it sometimes happens.
The trick is to insert repeatedly into a temporary table (which is primed with the root entries), including a column with the current iteration number, and doing an inner join between the most recent results in the temporary table and the child entries in the original table. Just break out of the loop when ##rowcount=0!
Simple eh?
I know you asked this question a while ago, but here is a solution that may work for detecting infinite recursive loops. I generate a path and I checked in the CTE condition if the USER ID is in the path, and if it is it wont process it again. Hope this helps.
Jose
DECLARE #Table TABLE(
USER_ID INT,
MANAGER_ID INT )
INSERT INTO #Table (USER_ID,MANAGER_ID) SELECT 1, 2
INSERT INTO #Table (USER_ID,MANAGER_ID) SELECT 2, 1
INSERT INTO #Table (USER_ID,MANAGER_ID) SELECT 3, 1
INSERT INTO #Table (USER_ID,MANAGER_ID) SELECT 4, 3
INSERT INTO #Table (USER_ID,MANAGER_ID) SELECT 5, 2
DECLARE #UserID INT
SELECT #UserID = 1
;with
UserTbl as -- Selects an employee and his subordinates.
(
select
'/'+cast( a.USER_ID as varchar(max)) as [path],
a.[User_ID],
a.[Manager_ID]
from #Table a
where [User_ID] = #UserID
union all
select
b.[path] +'/'+ cast( a.USER_ID as varchar(max)) as [path],
a.[User_ID],
a.[Manager_ID]
from #Table a
inner join UserTbl b
on (a.[Manager_ID]=b.[User_ID])
where charindex('/'+cast( a.USER_ID as varchar(max))+'/',[path]) = 0
)
select * from UserTbl
basicaly if you have loops like this in data you'll have to do the retreival logic by yourself.
you could use one cte to get only subordinates and other to get bosses.
another idea is to have a dummy row as a boss to both company owners so they wouldn't be each others bosses which is ridiculous. this is my prefferd option.
I can think of two approaches.
1) Produce more rows than you want, but include a check to make sure it does not recurse too deep. Then remove duplicate User records.
2) Use a string to hold the Users already visited. Like the not in subquery idea that didn't work.
Approach 1:
; with TooMuchHierarchy as (
select "User_ID"
, Manager_ID
, 0 as Depth
from "User"
WHERE "User_ID" = #UserID
union all
select U."User_ID"
, U.Manager_ID
, M.Depth + 1 as Depth
from TooMuchHierarchy M
inner join "User" U
on U.Manager_ID = M."user_id"
where Depth < 100) -- Warning MAGIC NUMBER!!
, AddMaxDepth as (
select "User_ID"
, Manager_id
, Depth
, max(depth) over (partition by "User_ID") as MaxDepth
from TooMuchHierarchy)
select "user_id", Manager_Id
from AddMaxDepth
where Depth = MaxDepth
The line where Depth < 100 is what keeps you from getting the max recursion error. Make this number smaller, and less records will be produced that need to be thrown away. Make it too small and employees won't be returned, so make sure it is at least as large as the depth of the org chart being stored. Bit of a maintence nightmare as the company grows. If it needs to be bigger, then add option (maxrecursion ... number ...) to whole thing to allow more recursion.
Approach 2:
; with Hierarchy as (
select "User_ID"
, Manager_ID
, '#' + cast("user_id" as varchar(max)) + '#' as user_id_list
from "User"
WHERE "User_ID" = #UserID
union all
select U."User_ID"
, U.Manager_ID
, M.user_id_list + '#' + cast(U."user_id" as varchar(max)) + '#' as user_id_list
from Hierarchy M
inner join "User" U
on U.Manager_ID = M."user_id"
where user_id_list not like '%#' + cast(U."User_id" as varchar(max)) + '#%')
select "user_id", Manager_Id
from Hierarchy
The preferrable solution is to clean up the data and to make sure you do not have any loops in the future - that can be accomplished with a trigger or a UDF wrapped in a check constraint.
However, you can use a multi statement UDF as I demonstrated here: Avoiding infinite loops. Part One
You can add a NOT IN() clause in the join to filter out the cycles.
This is the code I used on a project to chase up and down hierarchical relationship trees.
User defined function to capture subordinates:
CREATE FUNCTION fn_UserSubordinates(#User_ID INT)
RETURNS #SubordinateUsers TABLE (User_ID INT, Distance INT) AS BEGIN
IF #User_ID IS NULL
RETURN
INSERT INTO #SubordinateUsers (User_ID, Distance) VALUES ( #User_ID, 0)
DECLARE #Distance INT, #Finished BIT
SELECT #Distance = 1, #Finished = 0
WHILE #Finished = 0
BEGIN
INSERT INTO #SubordinateUsers
SELECT S.User_ID, #Distance
FROM Users AS S
JOIN #SubordinateUsers AS C
ON C.User_ID = S.Manager_ID
LEFT JOIN #SubordinateUsers AS C2
ON C2.User_ID = S.User_ID
WHERE C2.User_ID IS NULL
IF ##RowCount = 0
SET #Finished = 1
SET #Distance = #Distance + 1
END
RETURN
END
User defined function to capture managers:
CREATE FUNCTION fn_UserManagers(#User_ID INT)
RETURNS #User TABLE (User_ID INT, Distance INT) AS BEGIN
IF #User_ID IS NULL
RETURN
DECLARE #Manager_ID INT
SELECT #Manager_ID = Manager_ID
FROM UserClasses WITH (NOLOCK)
WHERE User_ID = #User_ID
INSERT INTO #UserClasses (User_ID, Distance)
SELECT User_ID, Distance + 1
FROM dbo.fn_UserManagers(#Manager_ID)
INSERT INTO #User (User_ID, Distance) VALUES (#User_ID, 0)
RETURN
END
You need a some method to prevent your recursive query from adding User ID's already in the set. However, as sub-queries and double mentions of the recursive table are not allowed (thank you van) you need another solution to remove the users already in the list.
The solution is to use EXCEPT to remove these rows. This should work according to the manual. Multiple recursive statements linked with union-type operators are allowed. Removing the users already in the list means that after a certain number of iterations the recursive result set returns empty and the recursion stops.
with UserTbl as -- Selects an employee and his subordinates.
(
select a.[User_ID], a.[Manager_ID] from [User] a WHERE [User_ID] = #UserID
union all
(
select a.[User_ID], a.[Manager_ID]
from [User] a join UserTbl b on (a.[Manager_ID]=b.[User_ID])
where a.[User_ID] not in (select [User_ID] from UserTbl)
EXCEPT
select a.[User_ID], a.[Manager_ID] from UserTbl a
)
)
select * from UserTbl;
The other option is to hardcode a level variable that will stop the query after a fixed number of iterations or use the MAXRECURSION query option hint, but I guess that is not what you want.