How to simplify following SQL query,
DECLARE #EMPLOYEE1 TABLE (EMPID INT,DEPT1 INT,DEPT2 INT)
DECLARE #EMPLOYEE2 TABLE (EMPID INT,DEPT1 INT,DEPT2 INT)
INSERT INTO #EMPLOYEE1 VALUES
(1,1,1),
(2,2,2),
(3,10,3),
(4,4,4)
INSERT INTO #EMPLOYEE2 VALUES
(1,1,1),
(2,2,2),
(3,10,10),
(4,10,4)
SELECT A.EMPID,
A.DEPT1 EMP1_DEPT,
0 TYPES
FROM #EMPLOYEE1 A
LEFT JOIN #EMPLOYEE2 B ON A.DEPT1=B.DEPT1
WHERE B.DEPT1 IS NULL
UNION ALL
SELECT A.EMPID,
A.DEPT2 EMP2_DEPT,
1 TYPES
FROM #EMPLOYEE1 A
LEFT JOIN #EMPLOYEE2 B ON A.DEPT2=B.DEPT2
WHERE B.DEPT2 IS NULL
can any one sort this problem, thanks in Advance
Here is one way to do it:
SELECT DISTINCT
A.EMPID,
CASE WHEN B.DEPT1 IS NULL THEN A.DEPT1 ELSE A.DEPT2 END As EMP1_DEPT,
CASE WHEN B.DEPT1 IS NULL THEN 0 ELSE 1 END As TYPES
FROM #EMPLOYEE1 A
LEFT JOIN #EMPLOYEE2 B ON A.DEPT1=B.DEPT1
LEFT JOIN #EMPLOYEE2 C ON A.DEPT2=C.DEPT2
WHERE B.DEPT1 IS NULL
OR C.DEPT2 IS NULL
Here is another alternative using CROSS APPLY and VALUES:
SELECT A.EMPID,
A_D.DEPT AS 'EMP1_DEPT',
A_D.[TYPES]
FROM #EMPLOYEE1 A
CROSS APPLY (VALUES (A.DEPT1, 0), (A.DEPT2, 1)) A_D ( DEPT, [TYPES] )
WHERE NOT EXISTS (SELECT 1
FROM #EMPLOYEE2 B
CROSS APPLY (VALUES (B.DEPT1, 0), (B.DEPT2, 1)) B_D ( DEPT, [TYPES] )
WHERE B_D.DEPT = A_D.DEPT
AND B_D.[TYPES] = A_D.[TYPES]);
The advantage of this approach is that each table is only hit once. It uses NOT EXISTS to improve performance in the query plan by using a Left Anti Semi Join.
Related
Query below works as planned, it shows exactly the way i joined it, and that is fine, but problem with it, is that if you have more "specialization" tables for users, something like "Mail type" or anything that user can have more then one data ... you would have to go two left joins for each and "give priority" via ISNULL (in this case)
I am wondering, how could I avoid using two joins and "give" priority to TypeId 2 over TypeId 1 in a single join, is that even possible?
if object_id('tempdb..#Tab1') is not null drop table #Tab1
create table #Tab1 (UserId int, TypeId int)
if object_id('tempdb..#Tab2') is not null drop table #Tab2
create table #Tab2 (TypeId int, TypeDescription nvarchar(50))
insert into #Tab1 (UserId, TypeId)
values
(1, 1),
(1, 2)
insert into #Tab2 (TypeId, TypeDescription)
values
(1, 'User'),
(2, 'Admin')
select *, ISNULL(t2.TypeDescription, t3.TypeDescription) [Role]
from #Tab1 t1
LEFT JOIN #Tab2 t2 on t1.TypeId = t2.TypeId and
t2.TypeId = 2
LEFT JOIN #Tab2 t3 on t1.TypeId = t3.TypeId and
t3.TypeId = 1
The first problem is determining priority. In this case, you could use the largest TypeId, but that does not seem like a great idea. You could add another column to serve as a priority ordinal instead.
From there, it is a top 1 per group query:
using top with ties and row_number():
select top 1 with ties
t1.UserId, t1.TypeId, t2.TypeDescription
from #Tab1 t1
left join #Tab2 t2
on t1.TypeId = t2.TypeId
order by row_number() over (
partition by t1.UserId
order by t2.Ordinal
--order by t1.TypeId desc
)
using common table expression and row_number():
;with cte as (
select t1.UserId, t1.TypeId, t2.TypeDescription
, rn = row_number() over (
partition by t1.UserId
order by t2.Ordinal
--order by t1.TypeId desc
)
from #Tab1 t1
left join #Tab2 t2
on t1.TypeId = t2.TypeId
)
select UserId, TypeId, TypeDescription
from cte
where rn = 1
rextester demo for both: http://rextester.com/KQAV36173
both return:
+--------+--------+-----------------+
| UserId | TypeId | TypeDescription |
+--------+--------+-----------------+
| 1 | 2 | Admin |
+--------+--------+-----------------+
Actually I don't think you don't need a join at all. But you have to take the max TypeID without respect to the TypeDescription, since these differences can defeat a Group By. So a workaround is to take the Max without TypeDescription initially, then subquery the result to get the TypeDescription.
SELECT dT.*
,(SELECT TypeDescription FROM #Tab2 T2 WHERE T2.TypeId = dT.TypeId) [Role] --2. Subqueries TypeDescription using the Max TypeID
FROM (
select t1.UserId
,MAX(T1.TypeId) [TypeId]
--, T1.TypeDescription AS [Role] --1. differences will defeat group by. Subquery for value later in receiving query.
from #Tab1 t1
GROUP BY t1.UserId
) AS dT
Produces Output:
UserId TypeId Role
1 2 Admin
Let's take an example. These are the rows of the table I want get the data:
The column I'm talking about is the reference one. The user can set this value on the web form, but the system I'm developing must suggest the lowest reference value still not used.
As you can see, the smallest value of this column is 35. I could just take the smaller reference and sum 1, but, in that case, the value 36 is already used. So, the value I want is 37.
Is there a way to do this without a loop verification? This table will grow so much.
This is for 2012+
DECLARE #Tbl TABLE (id int, reference int)
INSERT INTO #Tbl
( id, reference )
VALUES
(1, 49),
(2, 125),
(3, 35),
(4, 1345),
(5, 36),
(6, 37)
SELECT
MIN(A.reference) + 1 Result
FROM
(
SELECT
*,
LEAD(reference) OVER (ORDER BY reference) Tmp
FROM
#Tbl
) A
WHERE
A.reference - A.Tmp != -1
Result: 37
Here is yet another place where the tally table is going to prove invaluable. In fact it is so useful I keep a view on my system that looks like this.
create View [dbo].[cteTally] as
WITH
E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),
E2(N) AS (SELECT 1 FROM E1 a cross join E1 b), --10E+2 or 100 rows
E4(N) AS (SELECT 1 FROM E2 a cross join E2 b), --10E+4 or 10,000 rows max
cteTally(N) AS
(
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
)
select N from cteTally
Next of course we need some sample data and table to hold it.
create table #Something
(
id int identity
, reference int
, description varchar(10)
)
insert #Something (reference, description)
values (49, 'data1')
, (125, 'data2')
, (35, 'data3')
, (1345, 'data4')
, (36, 'data5')
, (7784, 'data6')
Now comes the magic of the tally table.
select top 1 t.N
from cteTally t
left join #Something s on t.N = s.reference
where t.N >= (select MIN(reference) from #Something)
and s.id is null
order by t.N
This is ugly, but should get the job done:
select
top 1 reference+1
from
[table]
where
reference+1 not in (select reference from [table])
order by reference
I used a table valued express to get the next value. I first left outer joined the table to itself (shifting the key in the join by +1). I then looked only at rows that had no corresponding match (b.ID is null). The minimum a.ReferenceID + 1 gives us the answer we are looking for.
create table MyTable
(
ID int identity,
Reference int,
Description varchar(20)
)
insert into MyTable values (10,'Data')
insert into MyTable values (11,'Data')
insert into MyTable values (12,'Data')
insert into MyTable values (15,'Data')
-- Find gap
;with Gaps as
(
select a.Reference+1 as 'GapID'
from MyTable a
left join MyTable b on a.Reference = b.Reference-1
where b.ID is null
)
select min(GapID) as 'NewReference'
from Gaps
NewReference
------------
13
I hope the code was clearer than my description.
CREATE TABLE #T(ID INT , REFERENCE INT, [DESCRIPTION] VARCHAR(50))
INSERT INTO #T
SELECT 1,49 , 'data1' UNION ALL
SELECT 2,125 , 'data2' UNION ALL
SELECT 3,35 , 'data3' UNION ALL
SELECT 4,1345, 'data4' UNION ALL
SELECT 5,36 , 'data5' UNION ALL
SELECT 6,7784, 'data6'
SELECT TOP 1 REFERENCE + 1
FROM #T T1
WHERE
NOT EXISTS
(
SELECT 1 FROM #T T2 WHERE T2.REFERENCE = T1.REFERENCE + 1
)
ORDER BY T1.REFERENCE
--- OR
SELECT MIN(REFERENCE) + 1
FROM #T T1
WHERE
NOT EXISTS
(
SELECT 1 FROM #T T2 WHERE T2.REFERENCE = T1.REFERENCE + 1
)
How about using a Tally table. The following illustrates the concept. It would be better to use a persisted numbers table as opposed to the cte however the code below illustrates the concept.
For further reading as to why you should use a persisted table, check out the following link: sql-auxiliary-table-of-numbers
DECLARE #START int = 1, #END int = 1000
CREATE TABLE #TEST(UsedValues INT)
INSERT INTO #TEST(UsedValues) VALUES
(1),(3),(5),(7),(9),(11),(13),(15),(17)
;With NumberSequence( Number ) as
(
Select #start as Number
union all
Select Number + 1
from NumberSequence
where Number < #end
)
SELECT MIN(Number)
FROM NumberSequence n
LEFT JOIN #TEST t
ON n.Number = t.UsedValues
WHERE UsedValues IS NULL
OPTION ( MAXRECURSION 1000 )
You could try using a descending order:
SELECT DISTINCT reference
FROM `Resultsados`
ORDER BY `reference` ASC;
As far as I know, there is no way to do this without a loop. To prevent multiple values from returning be sure to use DISTINCT.
I want to retrieve the parentid of an id, if that parentid has a parent again retrieve it, and so on.
Kind of hierarchy table.
id----parentid
1-----1
5-----1
47894--5
47897--47894
am new to sql server and tried, some queries like:
with name_tree as
(
select id, parentid
from Users
where id = 47897 -- this is the starting point you want in your recursion
union all
select c.id, c.parentid
from users c
join name_tree p on p.id = c.parentid -- this is the recursion
)
select *
from name_tree;
It is giving me only one row.
and also I want to insert these records into a temporary table variable.
How can I do this. thanks in advance. sorry for asking the simple question(though not to me)
Try this to get all parents of a child
;with name_tree as
(
select id, parentid
from Users
where id = 47897 -- this is the starting point you want in your recursion
union all
select C.id, C.parentid
from Users c
join name_tree p on C.id = P.parentid -- this is the recursion
-- Since your parent id is not NULL the recursion will happen continously.
-- For that we apply the condition C.id<>C.parentid
AND C.id<>C.parentid
)
-- Here you can insert directly to a temp table without CREATE TABLE synthax
select *
INTO #TEMP
from name_tree
OPTION (MAXRECURSION 0)
SELECT * FROM #TEMP
Click here to view result
EDIT :
If you want to insert into a table variable, you can do something like:
-- Declare table varialbe
Declare #TABLEVAR table (id int ,parentid int)
;with name_tree as
(
select id, parentid
from #Users
where id = 47897 -- this is the starting point you want in your recursion
union all
select C.id, C.parentid
from #Users c
join name_tree p on C.id = P.parentid -- this is the recursion
-- Since your parent id is not NULL the recursion will happen continously.
-- For that we apply the condition C.id<>C.parentid
AND C.id<>C.parentid
)
-- Here you can insert directly to table variable
INSERT INTO #TABLEVAR
select *
from name_tree
OPTION (MAXRECURSION 0)
SELECT * FROM #TABLEVAR
Click here to view result
Your query is doing recursion but in opposite direction. So if you change starting point to:
where id = 1
then you will have user 1 and all his successors
you didn't mention the desired output and input.
However you can try like this,
Declare #t table (id int ,parentid int)
insert into #t
select 1,1 union all
select 5,1 union all
select 47894,5 union all
select 47897,47894
;With CTE as
(
select * from #t where id=1
union all
Select a.* from #t a inner join cte b
on b.id=a.parentid and
a.id<>b.id
)
select * from cte
I have tow tables with the same number of rows
Example:
table a:
1,A
2,B
3,C
table b:
AA,BB
AAA,BBB,
AAAA,BBBB
I want a new table made like that in SQL SErver:
1,A,AA,BB
2,B,AAA,BBB
3,C,AAAA,BBBB
How do I do that?
In SQL Server 2005 (or newer), you can use something like this:
-- test data setup
DECLARE #tablea TABLE (ID INT, Val CHAR(1))
INSERT INTO #tablea VALUES(1, 'A'), (2, 'B'), (3, 'C')
DECLARE #tableb TABLE (Val1 VARCHAR(10), Val2 VARCHAR(10))
INSERT INTO #tableb VALUES('AA', 'BB'),('AAA', 'BBB'), ('AAAA', 'BBBB')
-- define CTE for table A - sort by "ID" (I just assumed this - adapt if needed)
;WITH DataFromTableA AS
(
SELECT ID, Val, ROW_NUMBER() OVER(ORDER BY ID) AS RN
FROM #tablea
),
-- define CTE for table B - sort by "Val1" (I just assumed this - adapt if needed)
DataFromTableB AS
(
SELECT Val1, Val2, ROW_NUMBER() OVER(ORDER BY Val1) AS RN
FROM #tableb
)
-- create an INNER JOIN between the two CTE which just basically selected the data
-- from both tables and added a new column "RN" which gets a consecutive number for each row
SELECT
a.ID, a.Val, b.Val1, b.Val2
FROM
DataFromTableA a
INNER JOIN
DataFromTableB b ON a.RN = b.RN
This gives you the requested output:
You could do a rank over the primary keys, then join on that rank:
SELECT RANK() OVER (table1.primaryKey),
T1.*,
T2.*
FROM
SELECT T1.*, T2.*
FROM
(
SELECT RANK() OVER (table1.primaryKey) [rank], table1.* FROM table1
) AS T1
JOIN
(
SELECT RANK() OVER (table2.primaryKey) [rank], table2.* FROM table2
) AS T2 ON T1.[rank] = T2.[rank]
Your query is strange, but in Oracle you can do this:
select a.*, tb.*
from a
, ( select rownum rn, b.* from b ) tb -- temporary b - added rn column
where a.c1 = tb.rn -- assuming first column in a is called c1
if there is not column with numbers in a you can do same trick twice
select ta.*, tb.*
from ( select rownum rn, a.* from a ) ta
, ( select rownum rn, b.* from b ) tb
where ta.rn = tb.rn
Note: be aware that this can generate random combination, for example
1 A AA BB
2 C A B
3 B AAA BBB
because there is no order by in ta and tb
I have a table that contains information on groups. There can be any number of members in a group. There is a group identifier and then an element identifier. I want to be able to in a single statement determine whether or not a given set exists in the table
#groupTable is an example of the data that already exists in the database
#inputData is the data that I want to see if it already exists in #groupTable
declare #groupData table
(
groupIdentifier int,
elementIdentifier uniqueidentifier
)
insert into #groupData values
(1, 'dfce40b1-3719-4e4c-acfa-65f728677700'),
(1, '89e7e6be-cee8-40a7-8135-a54659e0d88c')
declare #inputData table
(
tempGroupIdentifier int,
elementIdentifier uniqueidentifier
)
insert into #inputData values
(42, 'dfce40b1-3719-4e4c-acfa-65f728677700'),
(42, '89e7e6be-cee8-40a7-8135-a54659e0d88c'),
(55, 'dfce40b1-3719-4e4c-acfa-65f728677700'),
(55, '2395a42c-94f4-4cda-a773-221b26ea5e44'),
(55, 'f22db9df-a1f4-4078-b74c-90e34376eff6')
Now I want to run a query that will show the relationship of the sets, showing which groupIdentifier is associated with which tempGroupIdentifier. If there is no matching set then I need to know that too.
desired output:
groupIdentifier, tempGroupIdentifier
1, 42
null, 55
Does anyone any suggestions on how to approach this problem?
I could probably pivot the rows and concat all elementIdentifiers into a giant string for each group that then do equality on, but that doesn't seem like a good solution.
SELECT DISTINCT
T1.tempgroupIdentifier, T2.GroupIdentifier
FROM
(
SELECT
COUNT(*) OVER (PARTITION BY tempgroupIdentifier) AS GroupCount,
ROW_NUMBER() OVER (PARTITION BY tempgroupIdentifier ORDER BY elementIdentifier) AS GroupRN,
tempgroupIdentifier, elementIdentifier
FROM
#inputData
) T1
LEFT JOIN
(
SELECT
COUNT(*) OVER (PARTITION BY GroupIdentifier) AS GroupCount,
ROW_NUMBER() OVER (PARTITION BY GroupIdentifier ORDER BY elementIdentifier) AS GroupRN,
GroupIdentifier, elementIdentifier
FROM
#groupData
) T2 ON T1.elementIdentifier = T2.elementIdentifier AND
T1.GroupCount = T2.GroupCount AND
T1.GroupRN = T2.GroupRN
Edit: this will also deal with the same value in a given set
SELECT
(
CASE WHEN matchCount = gdCount AND matchCount = idCount
THEN groupIdentifier
ELSE NULL
END) groupIdentifier,
cj.tempGroupIdentifier
FROM
(
SELECT gd.groupIdentifier, id.tempGroupIdentifier, COUNT(1) matchCount
FROM #groupData gd
CROSS JOIN #inputData id
WHERE id.elementIdentifier = gd.elementIdentifier
GROUP BY gd.groupIdentifier, id.tempGroupIdentifier) as cj
CROSS APPLY (SELECT COUNT(groupIdentifier) from #groupData gdca WHERE gdca.groupIdentifier = cj.groupIdentifier) as gdc(gdCount)
CROSS APPLY (SELECT COUNT(tempGroupIdentifier) from #inputData idca WHERE idca.tempGroupIdentifier = cj.tempGroupIdentifier) as idc(idCount)