I have a table that has some children of a master object. Any child can occur more than once, and there is a Occurences column that contains that number, so the data in the table is something like:
ChildID | ParentID | Occurences
-------------------------------
1 | 1 | 2
2 | 1 | 2
3 | 2 | 1
4 | 2 | 3
I need to get a list of all the children, with each child appearing the corect number of times in the result, something like
IDENT | ChildID | ParentID
--------------------------
1 | 1 | 1
2 | 1 | 1
3 | 2 | 1
4 | 2 | 1
5 | 3 | 2
6 | 4 | 2
7 | 4 | 2
8 | 4 | 2
I can do this with a cursor that loops the table and inserts as many rows as neccessary, but I don't think that that is the best solution possible.
Thanks for the help
Create script included:
DECLARE #Children TABLE (ChildID int, ParentID int, Occurences int)
INSERT #Children
SELECT 1, 1, 2 UNION ALL
SELECT 2, 1, 2 UNION ALL
SELECT 3, 2, 1 UNION ALL
SELECT 4, 2, 3
;with C as
(
select ChildID,
ParentID,
Occurences - 1 as Occurences
from #Children
union all
select ChildID,
ParentID,
Occurences - 1 as Occurences
from C
where Occurences > 0
)
select row_number() over(order by ChildID) as IDENT,
ChildID,
ParentID
from C
order by IDENT
;WITH CTEs
AS
(
SELECT 1 [Id]
UNION ALL
SELECT [Id] + 1 FROM CTEs WHERE [Id] < 100
)
SELECT ROW_NUMBER() OVER(ORDER BY c1.ChildID, c1.ParentID) [rn]
, c1.ChildID, c1.ParentID
FROM CTEs ct
JOIN #Children c1 ON c1.Occurences >= ct.[Id]
Another way to generate sequence is using predefined table, e.g. master.dbo.spt_values:
SELECT ROW_NUMBER() OVER(ORDER BY c1.ChildID, c1.ParentID) [rn]
, c1.ChildID, c1.ParentID
FROM master.dbo.spt_values ct
JOIN #Children c1 ON c1.Occurences > ct.number
AND ct.type = 'P'
Related
ENTRY TABLE
__________________
| ID | PARENT_ID |
| 1 | null |
| 2 | 1 |
| 3 | 2 |
| 4 | null |
| 5 | 4 |
| 6 | 5 |
...
I make copies of the entries in some cases and they are conneted by parent ID.
Each entry can have one copy:
THIS WONT HAPPEN
__________________
| ID | PARENT_ID |
| 1 | null |
| 2 | 1 |
| 3 | 1 |
...
Sometimes I need to take a copy and query for it's top level parent. I need to find the top parent entries for all the entries I search for.
For example, if I query for the parents of ID 6 and 3, I would get ID 4 and 1.
If I query for the parents of ID 5 and 2, I would get ID 4 and 1.
But also If I query for ID 5 and 1, it should return ID 4 and 1 because the entry ID 1 is already the top parent itself.
I don't know where to begin since I don't know how to recursively query in such case.
Can anyone point me in the right direction?
I know that the query below will just return the child elemements (ID 6 and 3), but I don't know where to go from here honestly.
I am using OracleSQL by the way.
SELECT * FROM entry WHERE id IN (6, 3);
You can use a hierarchical query and CONNECT_BY_ROOT.
Either starting at the root of the hierarchy and working down:
SELECT id,
CONNECT_BY_ROOT(id) AS root_id
FROM entry
WHERE id IN (6, 3)
START WITH parent_id IS NULL
CONNECT BY PRIOR id = parent_id;
Or, from the entry back up to the root:
SELECT CONNECT_BY_ROOT(id) AS id,
id AS root_id
FROM entry
WHERE parent_id IS NULL
START WITH id IN (6, 3)
CONNECT BY PRIOR parent_id = id;
Which, for the sample data:
CREATE TABLE entry( id, parent_id ) AS
SELECT 1, NULL FROM DUAL UNION ALL
SELECT 2, 1 FROM DUAL UNION ALL
SELECT 3, 2 FROM DUAL UNION ALL
SELECT 4, NULL FROM DUAL UNION ALL
SELECT 5, 4 FROM DUAL UNION ALL
SELECT 6, 5 FROM DUAL UNION ALL
SELECT 7, 6 FROM DUAL
Both output:
ID
ROOT_ID
3
1
6
4
db<>fiddle here
You can use recursive CTE to walk the graph and find the initial parent. For example:
with
n (starting_id, current_id, parent_id, v) as (
select id, id, parent_id, 0 from entry where id in (6, 3)
union all
select n.starting_id, e.id, e.parent_id, n.v - 1
from n
join entry e on e.id = n.parent_id
)
select starting_id, current_id as initial_id
from (
select n.*, row_number() over(partition by starting_id order by v) as rn
from n
) x
where rn = 1
Result:
STARTING_ID INITIAL_ID
------------ ----------
3 1
6 4
See running example at db<>fiddle.
I have data table Customers that looks like this:
ID | Sequence No |
1 | 1 |
1 | 2 |
1 | 3 |
2 | 1 |
2 | 1 |
2 | 1 |
3 | 1 |
3 | 2 |
I would like to filter the table so that only IDs with more than 1 distinct count of Sequence No remain.
Expected output:
ID | Sequence No |
1 | 1 |
1 | 2 |
1 | 3 |
3 | 1 |
3 | 2 |
I tried
select ID, Sequence No
from Customers
where count(distinct Sequence No) > 1
order by ID
but I'm getting error. How to solve this?
You can get the desired result by using the below query. This is similar to what you were trying -
Sample Table & Data
Declare #Data table
(Id int, [Sequence No] int)
Insert into #Data
values
(1 , 1 ),
(1 , 2 ),
(1 , 3 ),
(2 , 1 ),
(2 , 1 ),
(2 , 1 ),
(3 , 1 ),
(3 , 2 )
Query
Select * from #Data
where ID in(
select ID
from #Data
Group by ID
Having count(distinct [Sequence No]) > 1
)
Using analytic functions, we can try:
WITH cte AS (
SELECT *, MIN([Sequence No]) OVER (PARTITION BY ID) min_seq,
MAX([Sequence No]) OVER (PARTITION BY ID) max_seq
FROM Customers
)
SELECT ID, [Sequence No]
FROM cte
WHERE min_seq <> max_seq
ORDER BY ID, [Sequence No];
Demo
We are checking for a distinct count of sequence number by asserting that the minimum and maximum sequence numbers are not the same for a given ID. The above query could benefit from the following index:
CREATE INDEX idx ON Customers (ID, [Sequence No]);
This would let the min and max values be looked up faster.
I've been trying hard to create a query to see all dependencies in a hierarchical organization. But the only I have accuaried is to retrieve the parent dependency. I have attached an image to show what I need.
Thanks for any clue you can give me.
This is the code I have tried with the production table.
WITH CTE AS
(SELECT
H1.systemuserid,
H1.pes_aprobadorid,
H1.yomifullname,
H1.internalemailaddress
FROM [dbo].[ext_systemuser] H1
WHERE H1.pes_aprobadorid is null
UNION ALL
SELECT
H2.systemuserid,
H2.pes_aprobadorid,
H2.yomifullname,
H2.internalemailaddress
FROM [dbo].[ext_systemuser] H2
INNER JOIN CTE c ON h2.pes_aprobadorid=c.systemuserid)
SELECT *
FROM CTE
OPTION (MAXRECURSION 1000)
You are almost there with your query. You just have to include all rows as a starting point. Also the join should be cte.parent_id = ext.user_id and not the other way round. I've done an example query in postgres, but you shall easily adapt it to your DBMS.
with recursive st_units as (
select 0 as id, NULL as pid, 'Director' as nm
union all select 1, 0, 'Department 1'
union all select 2, 0, 'Department 2'
union all select 3, 1, 'Unit 1'
union all select 4, 3, 'Unit 1.1'
),
cte AS
(
SELECT id, pid, cast(nm as text) as path, 1 as lvl
FROM st_units
UNION ALL
SELECT c.id, u.pid, cast(path || '->' || u.nm as text), lvl + 1
FROM st_units as u
INNER JOIN cte as c on c.pid = u.id
)
SELECT id, pid, path, lvl
FROM cte
ORDER BY lvl, id
id | pid | path | lvl
-: | ---: | :--------------------------------------- | --:
0 | null | Director | 1
1 | 0 | Department 1 | 1
2 | 0 | Department 2 | 1
3 | 1 | Unit 1 | 1
4 | 3 | Unit 1.1 | 1
1 | null | Department 1->Director | 2
2 | null | Department 2->Director | 2
3 | 0 | Unit 1->Department 1 | 2
4 | 1 | Unit 1.1->Unit 1 | 2
3 | null | Unit 1->Department 1->Director | 3
4 | 0 | Unit 1.1->Unit 1->Department 1 | 3
4 | null | Unit 1.1->Unit 1->Department 1->Director | 4
db<>fiddle here
I've reached this code that it is working but when I include a hierarchy table of more than 1800 the query is endless.
With cte AS
(select systemuserid, systemuserid as pes_aprobadorid, internalemailaddress, yomifullname
from #TestTable
union all
SELECT c.systemuserid, u.pes_aprobadorid, u.internalemailaddress, u.yomifullname
FROM #TestTable as u
INNER JOIN cte as c on c.pes_aprobadorid = u.systemuserid
)
select distinct * from cte
where pes_aprobadorid is not null
OPTION (MAXRECURSION 0)
My table has account_id and device_id. One account_id could have multiple device_ids and vice versa. I am trying to count the depth of each connected many-to-many relationship.
Ex:
account_id | device_id
1 | 10
1 | 11
1 | 12
2 | 10
3 | 11
3 | 13
3 | 14
4 | 15
5 | 15
6 | 16
How do I construct a query that knows to combine accounts 1-3 together, 4-5 together, and leave 6 by itself? All 7 entries of accounts 1-3 should be grouped together because they all touched the same account_id or device_id at some point. I am trying to group them together and output the count.
Account 1 was used on device's 10, 11, 12. Those devices used other accounts too so we want to include them in the group. They used additional accounts 2 and 3. But account 3 was further used by 2 more devices so we will include them as well. The expansion of the group brings in any other account or device that also "touched" an account or device already in the group.
A diagram is shown below:
You can use a recursive cte:
with recursive t(account_id, device_id) as (
select 1, 10 union all
select 1, 11 union all
select 1, 12 union all
select 2, 10 union all
select 3, 11 union all
select 3, 13 union all
select 3, 14 union all
select 4, 15 union all
select 5, 15 union all
select 6, 16
),
a as (
select distinct t.account_id as a, t2.account_id as a2
from t join
t t2
on t2.device_id = t.device_id and t.account_id >= t2.account_id
),
cte as (
select a.a, a.a2 as mina
from a
union all
select a.a, cte.a
from cte join
a
on a.a2 = cte.a and a.a > cte.a
)
select grp, array_agg(a)
from (select a, min(mina) as grp
from cte
group by a
) a
group by grp;
Here is a SQL Fiddle.
You can GROUP BY the device_id and then aggregate together the account_id into a Postgres array. Here is an example query, although I'm not sure what your actual table name is.
SELECT
device_id,
array_agg(account_id) as account_ids
FROM account_device --or whatever your table name is
GROUP BY device_id;
Results - hope it's what you're looking for:
16 | {6}
15 | {4,5}
13 | {3}
11 | {1,3}
14 | {3}
12 | {1}
10 | {1,2}
-- \i tmp.sql
CREATE TABLE graph(
account_id integer NOT NULL --references accounts(id)
, device_id integer not NULL --references(devices(id)
,PRIMARY KEY(account_id, device_id)
);
INSERT INTO graph (account_id, device_id)VALUES
(1,10) ,(1,11) ,(1,12)
,(2,10)
,(3,11) ,(3,13) ,(3,14)
,(4,15)
,(5,15)
,(6,16)
;
-- SELECT* FROM graph ;
-- Find the (3) group leaders
WITH seed AS (
SELECT row_number() OVER () AS cluster_id -- give them a number
, g.account_id
, g.device_id
FROM graph g
WHERE NOT EXISTS (SELECT*
FROM graph nx
WHERE (nx.account_id = g.account_id OR nx.device_id = g.device_id)
AND nx.ctid < g.ctid
)
)
-- SELECT * FROM seed;
;
WITH recursive omg AS (
--use the above CTE in a sub-CTE
WITH seed AS (
SELECT row_number()OVER () AS cluster_id
, g.account_id
, g.device_id
, g.ctid AS wtf --we need an (ordered!) canonical id for the tuples
-- ,just to identify and exclude them
FROM graph g
WHERE NOT EXISTS (SELECT*
FROM graph nx
WHERE (nx.account_id = g.account_id OR nx.device_id = g.device_id) AND nx.ctid < g.ctid
)
)
SELECT s.cluster_id
, s.account_id
, s.device_id
, s.wtf
FROM seed s
UNION ALL
SELECT o.cluster_id
, g.account_id
, g.device_id
, g.ctid AS wtf
FROM omg o
JOIN graph g ON (g.account_id = o.account_id OR g.device_id = o.device_id)
-- AND (g.account_id > o.account_id OR g.device_id > o.device_id)
AND g.ctid > o.wtf
-- we still need to exclude duplicates here
-- (which could occur if there are cycles in the graph)
-- , this could be done using an array
)
SELECT *
FROM omg
ORDER BY cluster_id, account_id,device_id
;
Results:
DROP SCHEMA
CREATE SCHEMA
SET
CREATE TABLE
INSERT 0 10
cluster_id | account_id | device_id
------------+------------+-----------
1 | 1 | 10
2 | 4 | 15
3 | 6 | 16
(3 rows)
cluster_id | account_id | device_id | wtf
------------+------------+-----------+--------
1 | 1 | 10 | (0,1)
1 | 1 | 11 | (0,2)
1 | 1 | 12 | (0,3)
1 | 1 | 12 | (0,3)
1 | 2 | 10 | (0,4)
1 | 3 | 11 | (0,5)
1 | 3 | 13 | (0,6)
1 | 3 | 14 | (0,7)
1 | 3 | 14 | (0,7)
2 | 4 | 15 | (0,8)
2 | 5 | 15 | (0,9)
3 | 6 | 16 | (0,10)
(12 rows)
Newer version (I added an Id column to the table)
-- for convenience :set of all adjacent nodes.
CREATE TEMP VIEW pair AS
SELECT one.id AS one
, two.id AS two
FROM graph one
JOIN graph two ON (one.account_id = two.account_id OR one.device_id = two.device_id)
AND one.id <> two.id
;
WITH RECURSIVE flood AS (
SELECT g.id, g.id AS parent_id
, 0 AS lev
, ARRAY[g.id]AS arr
FROM graph g
UNION ALL
SELECT c.id, p.parent_id AS parent_id
, 1+p.lev AS lev
, p.arr || ARRAY[c.id] AS arr
FROM graph c
JOIN flood p ON EXISTS (
SELECT * FROM pair WHERE p.id = pair.one AND c.id = pair.two)
AND p.parent_id < c.id
AND NOT p.arr #> ARRAY[c.id] -- avoid cycles/loops
)
SELECT g.*, a.parent_id
, dense_rank() over (ORDER by a.parent_id)AS group_id
FROM graph g
JOIN (SELECT id, MIN(parent_id) AS parent_id
FROM flood
GROUP BY id
) a
ON g.id = a.id
ORDER BY a.parent_id, g.id
;
New results:
CREATE VIEW
id | account_id | device_id | parent_id | group_id
----+------------+-----------+-----------+----------
1 | 1 | 10 | 1 | 1
2 | 1 | 11 | 1 | 1
3 | 1 | 12 | 1 | 1
4 | 2 | 10 | 1 | 1
5 | 3 | 11 | 1 | 1
6 | 3 | 13 | 1 | 1
7 | 3 | 14 | 1 | 1
8 | 4 | 15 | 8 | 2
9 | 5 | 15 | 8 | 2
10 | 6 | 16 | 10 | 3
(10 rows)
I have a Power table that stores building circuit details. A circuit can be 1 phase or 3 phase but is always represented as 1 row in the circuit table.
I want to insert the details of the circuits into a join table which joins panels to circuits
My current circuit table has the following details
CircuitID | Voltage | Phase | PanelID | Cct |
1 | 120 | 1 | 1 | 1 |
2 | 208 | 3 | 1 | 3 |
3 | 208 | 2 | 1 | 8 |
Is it possible to create a select where by when it sees a 3 phase row it selects 3 rows (or 2 select 2 rows) and increments the Cct column by 1 each time or do I have to create a loop?
CircuitID | PanelID | Cct |
1 | 1 | 1 |
2 | 1 | 3 |
2 | 1 | 4 |
2 | 1 | 5 |
3 | 1 | 8 |
3 | 1 | 9 |
Here is one way to do it
First generate numbers using tally table(best possible way). Here is one excellent article about generating number without loops. Generate a set or sequence without loops
Then join the numbers table with yourtable where phase value of each record should be greater than sequence number in number's table
;WITH e1(n) AS
(
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL
SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
), -- 10
e2(n) AS (SELECT 1 FROM e1 CROSS JOIN e1 AS b), -- 10*10
e3(n) AS (SELECT 1 FROM e1 CROSS JOIN e2), -- 10*100
numbers as ( SELECT n = ROW_NUMBER() OVER (ORDER BY n) FROM e3 )
SELECT CircuitID,
PanelID,
Cct = Cct + ( n - 1 )
FROM Yourtable a
JOIN numbers b
ON a.Phase >= b.n
You can do this with a one recursive cte.
WITH cte AS
(
SELECT [CircuitID], [Voltage], [Phase], [PanelID], [Cct], [Cct] AS [Ref]
FROM [Power]
UNION ALL
SELECT [CircuitID], [Voltage], [Phase], [PanelID], [Cct] + 1, [Ref]
FROM cte
WHERE [Cct] + 1 < [Phase] + [Ref]
)
SELECT [CircuitID], [PanelID], [Cct]
FROM cte
ORDER BY [CircuitID]
Simplest way,
Select y.* from (
Select 1 CircuitID,120 Voltage,1 Phase,1 PanelID, 1 Cct
union
Select 2,208,3,1,3
union
Select 3,208,2,1,8)y,
(Select 1 x
union
Select 2 x
union
Select 3 x)x
Where x.x <= y.Phase
Directly copy paste this and try, it will run 100%. After that, just replace my 'y' table with your real table.