T-sql CTE recursion - tsql

I just want it to return
1
2
WITH
CTE1 AS
(
select value
UNION ALL
select value=value+1
FROM CTe1
WHERE value =2
)
select * from cte1
how come that doesnt work.


The following will print out 1, 2:
WITH
CTE1 AS
(
select 1 as value
UNION ALL
select value=value+1
FROM CTe1
WHERE value = 1
)
select * from cte1
The problem was that value was not defined for your first CTE clause. I assume you wanted 1. Then the second CTE clause self-references the first one and adds 1.


The CTE will print 1 and 2 as rows. Is this what you are after?
WITH
CTE1 AS
(
select 1 as value
UNION ALL
select value=value+1
FROM CTe1
WHERE value < 2
)
select * from cte1


here is a code to search a string for a character macth thank you all.
Begin
with recursiveCTE(matchNumber, foundAt) as (
select 1, charindex(#toFind, #ToSearch, 0)
union all
select matchNumber + 1, charindex(#toFind, #ToSearch, foundAt + 1)
from recursiveCTE where foundAt > 0
)
select
matchNumber as "Match Number",
(case when foundAt = 0 then null else foundAt end) as "Found At"
from recursiveCTE
where foundAt 0 or matchNumber = 1
;
end;

Related

Ho do i convert this code into PostgreSQL Store Procedure?

I am new to PostgreSQL. I want to converter or add this code to Store Procedure.
WITH RECURSIVE t(i) AS (
SELECT * FROM unnest((select regexp_split_to_array('signature',''))::char[])
), cte AS (
SELECT i AS combo, i, 1 AS ct
FROM t
UNION ALL
SELECT cte.combo || t.i, t.i, ct + 1
FROM cte, t
WHERE ct <= 8
AND position(t.i in cte.combo) = 0
)
SELECT distinct cc.combo,ww.word
FROM cte cc
inner join words ww ON ww.word=cc.combo
WHERE length(combo)>1
AND ww.source_id in(1,2,19,21,24,26,33,34)
ORDER BY cc.combo ASC;

Just put it into a function:
create function generate_anagrams(p_word text)
returns table(combo text, word text)
as
$$
WITH RECURSIVE t(i) AS (
SELECT *
FROM unnest((select regexp_split_to_array(p_word,''))::char[])
), cte AS (
SELECT i AS combo, i, 1 AS ct
FROM t
UNION ALL
SELECT cte.combo || t.i, t.i, ct + 1
FROM cte, t
WHERE ct <= 8
AND position(t.i in cte.combo) = 0
)
SELECT distinct cc.combo,ww.word
FROM cte cc
inner join words ww ON ww.word=cc.combo
WHERE length(combo)>1
AND ww.source_id in(1,2,19,21,24,26,33,34)
ORDER BY cc.combo ASC
$$
language sql;
You can use it like this:
select *
from generate_anagrams('signature');

postgresql combining several periods into one

I'm trying to combine range.
WITH a AS (
select '2017-09-16 07:12:57' as begat,'2017-09-16 11:30:22' as endat
union
select '2017-09-18 17:05:21' ,'2017-09-19 13:18:01'
union
select '2017-09-19 15:34:40' ,'2017-09-22 13:29:37'
union
select '2017-09-22 12:24:16' ,'2017-09-22 13:18:29'
union
select '2017-09-28 09:48:54' ,'2017-09-28 13:39:13'
union
select '2017-09-20 13:52:43' ,'2017-09-20 14:14:43'
), b AS (
SELECT *, lag(endat) OVER (ORDER BY begat) < begat OR NULL AS step
FROM a
)
, c AS (
SELECT *, count(step) OVER (ORDER BY begat) AS grp
FROM b
)
SELECT min(begat), coalesce( max(endat), 'infinity' ) AS range
FROM c
GROUP BY grp
ORDER BY 1
Result
1 "2017-09-16 07:12:57";"2017-09-16 11:30:22"
2 "2017-09-18 17:05:21";"2017-09-19 13:18:01"
3 "2017-09-19 15:34:40";"2017-09-22 13:29:37"
4 "2017-09-22 12:24:16";"2017-09-22 13:18:29"
5 "2017-09-28 09:48:54";"2017-09-28 13:39:13"
positions 3,4 intersect (endata> next begat)
How do I make the union of all the intersections into one large interval
I need result
1 "2017-09-16 07:12:57";"2017-09-16 11:30:22"
2 "2017-09-18 17:05:21";"2017-09-19 13:18:01"
3 "2017-09-19 15:34:40";"2017-09-22 13:29:37"
4 "2017-09-28 09:48:54";"2017-09-28 13:39:13"

Hey I would suggest using the following process :
1- Identify when a row is new, so you give a value of 1 to values that do not overlap (CTE b)
2- Sequence together the rows that have overlaps with others. This way you can see have a common identifier that will allow you to MAX and MIN begat and endat (CTE c)
3- For each sequence, give the MIN of begat and the MAX of endat so you will have your final values
WITH a AS (
select '2017-09-16 07:12:57' as begat,'2017-09-16 11:30:22' as endat
union
select '2017-09-18 17:05:21' ,'2017-09-19 13:18:01'
union
select '2017-09-19 15:34:40' ,'2017-09-22 13:29:37'
union
select '2017-09-22 12:24:16' ,'2017-09-22 13:18:29'
union
select '2017-09-28 09:48:54' ,'2017-09-28 13:39:13'
union
select '2017-09-20 13:52:43' ,'2017-09-20 14:14:43'
)
, b AS (
SELECT
begat
, endat
, (begat > MAX(endat) OVER w IS TRUE)::INT is_new
FROM a
WINDOW w AS (ORDER BY begat ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)
)
, c AS (
SELECT
begat
, endat
, SUM((is_new)) OVER (ORDER BY begat) seq
FROM b
)
SELECT
MIN(begat) beg_at
, MAX(endat) end_at
FROM c
GROUP BY seq

EDITED
If you need speed you can use a psql function:
create or replace function append_ranges_in_a() returns setof a
language plpgsql
as
$BODY$
declare
v_current a%rowtype;
v_new a%rowtype;
v_first boolean:=true;
begin
for v_current in select begat, endat from a order by begat, endat
loop
if v_first then
v_first := false;
v_new.begat := v_current.begat;
elsif v_new.endat < v_current.begat then
return next v_new;
v_new.begat := v_current.begat;
end if;
v_new.endat := greatest(v_current.endat,v_new.endat);
end loop;
return next v_new;
return;
end;
$BODY$;
select * from append_ranges_in_a()
I test it with ~ 400000 rows:
delete from a;
insert into a (begat, endat)
select time::text, (time+'1 day'::interval)::text
from (select t+(round(random()*23.0)||' hours')::interval as time
from generate_series('1401-01-01'::timestamp,'2018-08-21'::timestamp,'1 day'::interval) t
) t;
select count(*) from a;
select * from append_ranges_in_a() offset 100000 limit 10
and it is twice fast as O(n^2) pure SQL version.
OLD slow solution:
You can use a recursive WITH query https://www.postgresql.org/docs/current/static/queries-with.html to construct the result row by row.
I create the table
The first row is the candidate first row (ending where ending), but the row is not "ready"
Then I look at the next row (step) and if it is not intersecting I add a ready row,
Also I add a not ready row with the current (last) observed range
When I do not have more rows I calculate the last row
I retain ready rows and the last row
Here is the code
CREATE TABLE a as
select '2017-09-16 07:12:57' as begat,'2017-09-16 11:30:22' as endat
union
select '2017-09-18 17:05:21' ,'2017-09-19 13:18:01'
union
select '2017-09-19 15:34:40' ,'2017-09-22 13:29:37'
union
select '2017-09-22 12:24:16' ,'2017-09-22 13:18:29'
union
select '2017-09-28 09:48:54' ,'2017-09-28 13:39:13'
union
select '2017-09-20 13:52:43' ,'2017-09-20 14:14:43';
WITH RECURSIVE t(begat, endat, ready, step) AS (
select * from (
select *,false,1 from a order by begat, endat limit 1) a
UNION ALL
SELECT new_rows.*
FROM (SELECT * FROM t ORDER BY begat DESC limit 1) t,
lateral (SELECT * FROM a ORDER BY begat, endat OFFSET step LIMIT 1) a,
lateral (
SELECT t.begat, t.endat, true as ready, step WHERE t.endat < a.begat
UNION SELECT CASE WHEN t.endat < a.begat THEN a.begat ELSE t.begat END, greatest(a.endat, t.endat), false, step+1
) new_rows
)
select begat, endat
from (
select begat, endat, ready, row_number() over (order by begat desc, endat desc)=1 is_last
from t
order by begat, endat) t
where ready or is_last;

i using range type
https://www.postgresql.org/docs/9.3/static/rangetypes.html
WITH tmp AS (
-- preparation range type
select begat, coalesce( endat, 'infinity' ) as endAt, tsrange( begat, coalesce( endat, 'infinity' ) ) as rg
from (
select '2017-09-11 17:13:03'::timestamp as begat ,'2017-09-12 12:24:09'::timestamp as endat union
select '2017-09-19 15:34:40','2017-09-20 11:04:45' union
select '2017-09-20 08:32:00','2017-09-22 13:28:37' union
select '2017-09-20 13:52:43','2017-09-20 14:14:43' union
select '2017-09-21 12:24:16','2017-09-21 13:28:29' union
select '2017-09-22 12:24:16','2017-09-22 13:28:29' union
select '2017-09-22 12:34:16','2017-09-23 13:28:29' union
select '2017-09-22 12:25:16','2017-09-24 13:28:29' union
select '2017-09-28 09:48:54','2017-09-28 13:39:13' union
select '2017-09-28 14:22:16','2017-09-28 15:52:15' union
select '2017-10-05 12:17:45','2017-10-06 12:35:38' union
select '2017-10-06 16:20:44','2017-10-07 10:11:09' union
select '2017-10-07 20:38:32','2017-10-09 14:42:29' union
select '2017-10-12 18:22:14','2017-10-12 20:52:45'
) a
),a as (
-- group intersecting range
select l.*
from tmp l left join tmp r on l.begAt > r.begAt and r.rg #> l.rg
where r.begAt is null
),
b AS (
SELECT *, lag(endat) OVER (ORDER BY begat) < begat OR NULL AS step
FROM a
)
, c AS (
SELECT *, count(step) OVER (ORDER BY begat) AS grp
FROM b
)
SELECT min(begat), coalesce( max(endat), 'infinity' ) AS range
FROM c
GROUP BY grp
ORDER BY 1

Subtraction of sub query counts DB2

i am trying to take the difference of the counts of 2 sub queries. But i get the following error. I executed the two sub queries separately and it works fine. The error may be because way i try to convert them to a single query. Any ideas?
select
(select count(*) FROM TESTEA.AIT_P_NUMBER where
rtrim(ltrim(translate(PNU_POL,' ','1234567890'))) = '')
-
(select count(*) FROM TESTEA.AIT_P_NUMBER )

Can you try selecting from DUAL:
SELECT
(SELECT COUNT(*) FROM TESTEA.AIT_P_NUMBER
WHERE RTRIM(LTRIM(TRANSLATE(PNU_POL, ' ', '1234567890'))) = '') -
(SELECT COUNT(*) FROM TESTEA.AIT_P_NUMBER)
FROM DUAL;
Actually, there is a single query workaround you can use involving conditional aggregation:
SELECT
SUM(CASE WHEN RTRIM(LTRIM(TRANSLATE(PNU_POL, ' ', '1234567890'))) = ''
THEN 1 ELSE 0 END) - COUNT(*)
FROM TESTEA.AIT_P_NUMBER

Solution 1 :
values (SELECT COUNT(*) FROM TESTEA.AIT_P_NUMBER where trim(translate(PNU_POL,' ','1234567890')) = '')
- (SELECT COUNT(*) nb FROM TESTEA.AIT_P_NUMBER)

Solution 2 :
SELECT sum(case when trim(translate(PNU_POL,' ','1234567890')) = '' then 1 else 0 end) - count(*)
FROM TESTEA.AIT_P_NUMBER

Solution 3 :
select (SELECT COUNT(*) FROM TESTEA.AIT_P_NUMBER where trim(translate(PNU_POL,' ','1234567890')) = '')
- (SELECT COUNT(*) nb FROM TESTEA.AIT_P_NUMBER)
from SYSIBM.SYSDUMMY1

Solution 4 :
select sum(nb) from
(
select count(*) nb
from TESTEA.AIT_P_NUMBER where trim(translate(PNU_POL,' ','1234567890')) = ''
union all
select -count(*) nb
from TESTEA.AIT_P_NUMBER
) nb

sql recursive within a range

I have a sql query to form a parent/child structure to a tree-like view, the outcome is like this:
lvl1a
lvl1a/lvl2a
lvl1a/lvl2b
lvl1b/lvl2a/lvl3a
lvl1c
lvl1d/lvl2a/lvl3a/lvl4a
...
the query itself doesn't have a limited range, for instance, if i only want to get this tree-like view for the first and second level
can someone modify the sql query to add such function? tks
;with cte as
(
select
labelID,
Title,
ParentLevel,
cast(Title as varchar(max)) as [treePath]
from TestTable
where ParentLevel = 0
union all
select
t.labelID,
t.Title,
t.ParentLevel,
[treePath] + '/' + cast(t.Title as varchar(255))
from
cte
join TestTablet on cte.labelID = t.ParentLevel
)
select
labelID,
Title,
ParentLevel,
[treePath]
from cte
order by treePath

All we did here was add lvl 0 for the first part of the union in the CTE
then increment it by 1 each time the recursion occurs (after the union all)
then add a where clause to the select to eliminate levels beyond 2.
Though I find it odd this works since t isn't aliased in your code...
.
;with cte as
(
select
labelID,
Title,
ParentLevel,
cast(Title as varchar(max)) as [treePath],
0 as lvl
from TestTable
where ParentLevel = 0
union all
select
t.labelID,
t.Title,
t.ParentLevel,
[treePath] + '/' + cast(t.Title as varchar(255)),
cte.lvl+1 as lvl
from
cte
join TestTablet t on cte.labelID = t.ParentLevel
)
select
labelID,
Title,
ParentLevel,
[treePath]
from cte
where lvl <=2
order by treePath

SQL Running Subtraction and Deviation

-- Just a brief of business scenario is table has been created for a good receipt.
-- So here we have good expected line with PurchaseOrder(PO) in first few line.
-- And then we receive each expected line physically and that time these quantity may be different
-- due to business case like quantity may damage and short quantity like that.
-- So we maintain a status for that eg: OK, Damage, also we have to calculate short quantity
-- based on total of expected quantity of each item and total of received line.
if object_id('DEV..Temp','U') is not null
drop table Temp
CREATE TABLE Temp
(
ID INT IDENTITY(1,1) PRIMARY KEY CLUSTERED,
Item VARCHAR(32),
PO VARCHAR(32) NULL,
ExpectedQty INT NULL,
ReceivedQty INT NULL,
[STATUS] VARCHAR(32) NULL,
BoxName VARCHAR(32) NULL
)
-- Please see first few line with PO data will be the expected lines,
-- and then rest line will be received line
INSERT INTO TEMP (Item,PO,ExpectedQty,ReceivedQty,[STATUS],BoxName)
SELECT 'ITEM01','PO-01','30',NULL,NULL,NULL UNION ALL
SELECT 'ITEM01','PO-02','20',NULL,NULL,NULL UNION ALL
SELECT 'ITEM02','PO-01','40',NULL,NULL,NULL UNION ALL
SELECT 'ITEM03','PO-01','50',NULL,NULL,NULL UNION ALL
SELECT 'ITEM03','PO-02','30',NULL,NULL,NULL UNION ALL
SELECT 'ITEM03','PO-03','20',NULL,NULL,NULL UNION ALL
SELECT 'ITEM04','PO-01','30',NULL,NULL,NULL UNION ALL
SELECT 'ITEM01',NULL,NULL,'20','OK','box01' UNION ALL
SELECT 'ITEM01',NULL,NULL,'25','OK','box02' UNION ALL
SELECT 'ITEM01',NULL,NULL,'5','DAMAGE','box03' UNION ALL
SELECT 'ITEM02',NULL,NULL,'38','OK','box04' UNION ALL
SELECT 'ITEM02',NULL,NULL,'2','DAMAGE','box05' UNION ALL
SELECT 'ITEM03',NULL,NULL,'30','OK','box06' UNION ALL
SELECT 'ITEM03',NULL,NULL,'30','OK','box07' UNION ALL
SELECT 'ITEM03',NULL,NULL,'10','DAMAGE','box09' UNION ALL
SELECT 'ITEM04',NULL,NULL,'25','OK','box10'
-- Below Table is my expected result based on above data.
-- I need to show those data following way.
-- So I appreciate if you can give me an appropriate query for it.
-- Note: first row is blank and it is actually my table header. :)
-- Conditions : any of row, we cant have ReceivedQty, DamageQty and ShortQty
-- values more than ExpectedQty value. Item03 has this scenario
-- Query should run in SQL 2000 DB
SELECT ''as'ITEM', ''as'PO#', ''as'ExpectedQty',''as'ReceivedQty',''as'DamageQty' ,''as'ShortQty' UNION ALL
SELECT 'ITEM01','PO-01','30','30','0' ,'0' UNION ALL
SELECT 'ITEM01','PO-02','20','15','5' ,'0' UNION ALL
SELECT 'ITEM02','PO-01','40','38','2' ,'0' UNION ALL
SELECT 'ITEM03','PO-01','50','50','0' ,'0' UNION ALL
SELECT 'ITEM03','PO-02','30','20','10' ,'10' UNION ALL
SELECT 'ITEM03','PO-03','20','0','0','20' UNION ALL
SELECT 'ITEM04','PO-01','30','25','0' ,'5'

Using this solution as a starting point, I've eventually ended up with this:
SELECT
Item,
PO,
ExpectedQty,
ReceivedQty = CASE
WHEN RemainderQty >= 0 THEN ExpectedQty
WHEN RemainderQty < -ExpectedQty THEN 0
ELSE RemainderQty + ExpectedQty
END,
DamageQty = CASE
WHEN RemainderQty >=0 OR ExpectedQty < -TotalRemainderQty THEN 0
WHEN RemainderQty < -ExpectedQty AND TotalRemainderQty > 0 THEN ExpectedQty
WHEN RemainderQty < -ExpectedQty AND TotalRemainderQty < -DamagedQty THEN ExpectedQty + TotalRemainderQty
WHEN RemainderQty > -DamagedQty THEN -RemainderQty
ELSE DamagedQty
END,
ShortQty = CASE
WHEN TotalRemainderQty >= 0 THEN 0
WHEN TotalRemainderQty < -ExpectedQty THEN ExpectedQty
ELSE -TotalRemainderQty
END
FROM (
SELECT
a.Item,
a.PO,
a.ExpectedQty,
b.DamagedQty,
RemainderQty = b.ReceivedQty - a.RunningTotalQty,
TotalRemainderQty = b.ReceivedQty + b.DamagedQty - a.RunningTotalQty
FROM (
SELECT
a.Item,
a.PO,
a.ExpectedQty,
RunningTotalQty = SUM(a2.ExpectedQty)
FROM (SELECT Item, PO, ExpectedQty FROM Temp WHERE STATUS IS NULL) AS a
INNER JOIN (SELECT Item, PO, ExpectedQty FROM Temp WHERE STATUS IS NULL) AS a2
ON a.Item = a2.Item AND a.PO >= a2.PO
GROUP BY
a.Item,
a.PO,
a.ExpectedQty
) a
LEFT JOIN (
SELECT
Item,
ReceivedQty = SUM(CASE STATUS WHEN 'OK' THEN ReceivedQty ELSE 0 END),
DamagedQty = SUM(CASE STATUS WHEN 'DAMAGE' THEN ReceivedQty ELSE 0 END)
FROM Temp
GROUP BY Item
) b ON a.Item = b.Item
) s;