Is it possible to return multiple column on single CASE evaluation in DB2?
below query return single column.
select (case when 1=1 then 0 else 1 end) as col from table;
I need multiple column like
select (case when 1=1 then 0 as col, 1 as col1 else 2 as col1 , 3 as col2 end) from table;
select (case when 1=1 then 0,1 else 2, 3 end)col , col1 from table;
Is coalesce function is use full for above conditions? thanks.
It’s not possible with a single CASE statement in Db2.
But you may use something like below.
select
coalesce(t1.c1, t2.c1, t3.c1) c1
, coalesce(t1.c2, t2.c2, t3.c2) c2
from
(
select tabschema, tabname, rownumber() over (partition by tabschema) rn_
from syscat.tables
) b
left join table(values ('_SYSIBM_', b.tabname)) t1 (c1, c2) on b.tabschema='SYSIBM'
left join table(values ('_SYSCAT_', b.tabname)) t2 (c1, c2) on b.tabschema='SYSCAT'
cross join table(values (b.tabschema, b.tabname)) t3 (c1, c2)
where b.rn_=1;
The sub-select on syscat.tables is constructed to return only one table from each schema just to show the idea (your base table must be there instead of it). "Case condition" here is what you see in the on clause of each join. "Returned values" of this "Case expression" are inside the values clauses.
A CASE statement can be re-written as a UNION. Logically they are the same thing.
So, you could do this
select 0 as col, 1 as col1 from table where 1=1
UNION ALL
select 2 as col, 3 as col1 from table where NOT 1=1 OR 1=1 IS NULL
I have the following issue. I have products with 3 different states. Parent, Child and products which are orphans. I am setting Parents as 1, Children as 2 and Orphans as 0. I am struggling to get the Orphan to set to 0. I realise that counting the amount of Parent PLU's is where I am going wrong but I do not know how to resolve this issue. Any help would be appreciated. (As you maybe able to tell, I am a noob and constructive criticism would be appreciated)
Kind Regards,
Jason.
Picture of results from query
declare #OrderID int = 1635
declare #Store char(3) = '001'
declare #SortedBy smallint = 2
DECLARE #tbl TABLE (DetailID int, OrderID int, PLU nvarchar(35), ParentPLU nvarchar(35))
INSERT INTO #tbl (DetailID, OrderID, PLU, ParentPLU)
SELECT DetailID, OrderDetails.OrderID, OrderDetails.PLU, OrderDetails.ParentPLU
FROM OrderDetails
INNER JOIN PLU
ON PLU.PLU = OrderDetails.PLU
WHERE OrderDetails.OrderID = #OrderID
AND OrderDetails.OrderStore = #Store
SELECT DetailID, OrderID, PLU, ParentPLU,
CASE WHEN ( SELECT COUNT(DISTINCT ParentPLU)
FROM #tbl
WHERE ParentPLU IN (SELECT PLU FROM #tbl)
) > 0 AND ParentPLU = '' THEN 1
WHEN ( SELECT COUNT(DISTINCT ParentPLU)
FROM #tbl
WHERE ParentPLU IN (SELECT PLU FROM #tbl)
) > 0 THEN 2
ELSE
0
END AS ParentChild,
ROW_NUMBER() OVER (ORDER BY
CASE WHEN #SortedBy = 1 THEN OrderID END ASC,
CASE WHEN #SortedBy = 2 THEN DetailID END ASC
) AS ID
FROM #tbl
You can use coalesce to get your desired result. First subquery checks for parent state, second for children. If both are null, then it is orphan
select
DetailID, OrderID, PLU, ParentPLU
, coalesce((
select
distinct 1
from
#tbl b
where
a.PLU = b.ParentPlu
)
, (
select
distinct 2
from
#tbl b
where
b.PLU = a.ParentPlu
), 0)
from
#tbl a
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
Lets say I have table with ID int, VALUE string:
ID | VALUE
1 abc
2 abc
3 def
4 abc
5 abc
6 abc
If I do select value, count(*) group by value I should get
VALUE | COUNT
abc 5
def 1
Now the tricky part, if there is count == 1 I need to get that ID from first table. Should I be using CTE? creating resultset where I will add ID string == null and run update b.ID = a.ID where count == 1 ?
Or is there another easier way?
EDIT:
I want to have result table like this:
ID VALUE count
null abc 5
3 def 1
If your ID values are unique, you can simply check to see if the max(id) = min(id). If so, then use either one, otherwise you can return null. Like this:
Select Case When Min(id) = Max(id) Then Min(id) Else Null End As Id,
Value, Count(*) As [Count]
From YourTable
Group By Value
Since you are already performing an aggregate, including the MIN and Max function is not likely to take any extra (noticeable) time. I encourage you to give this a try.
The way I would do it would indeed be a CTE:
using #group AS (SELECT value, Count(*) as count from MyTable GROUP BY value HAVING count = 1)
SELECT MyTable.ID, #group.value, #group.count from MyTable
JOIN #group ON #group.value = MyTable.value
When using group by, after the group by statement you can use a having clause.
So
SELECT [ID]
FROM table
GROUP BY [VALUE]
HAVING COUNT(*) = 1
Edit: with regards to your edited question: this uses some fun joins and unions
CREATE TABLE #table
(ID int IDENTITY,
VALUE varchar(3))
INSERT INTO #table (VALUE)
VALUES('abc'),('abc'),('def'),('abc'),('abc'),('abc')
SELECT * FROM (
SELECT Null as ID,VALUE, COUNT(*) as [Count]
FROM #table
GROUP BY VALUE
HAVING COUNT(*) > 1
UNION ALL
SELECT t.ID,t.VALUE,p.Count FROM
#table t
JOIN
(SELECT VALUE, COUNT(*) as [Count]
FROM #table
GROUP BY VALUE
HAVING COUNT(*) = 1) p
ON t.VALUE=p.VALUE
) a
DROP TABLE #table
maybe not the most efficient but something like this works:
SELECT MAX(Id) as ID,Value FROM Table WHERE COUNT(*) = 1 GROUP BY Value
-- 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;