TERADATA, CASE INTO WHERE CLAUSE - sql

Question

I'd need help on this matter.
my where condition does not get accepted ... I know that is tricky the case in the where clause, so i think you could let me out... I created a field into a subquery with a over partition by, which then i bring into the main select ... then I'd need to apply the filter you see below... it returns me an error saying that B does not exist even tough if I just write B.CC = 1 then it gives me result...
any ideas?
Thanks in advance
SELECT
B.*
FROM
(
SELECT
A.*,
(Count(A.COD_ABI) Over (PARTITION BY A.COD_ABI, A.COD_KTO)) AS CC
FROM (
SELECT DISTINCT
T2.COD_PRODT_SALDO,
T2.COD_RESID_NPE,
T2.COD_DIVISA_UIC,
T2.COD_ABI,
T2.COD_NDG,
T2.COD_KTO,
T2.COD_PAESE_UIC_NPE,
T2.DAT_SCA,
T2.DAT_ACC,
T2.DAT_EST
FROM
(
SELECT
T1.COD_PRODT_SALDO
,T1.COD_RESID_NPE
,T1.COD_DIVISA_UIC
,T1.COD_ABI
,T1.COD_NDG
,'00753' ||T1.COD_PRODT_SALDO||T1.COD_CNTRT_SALDO AS COD_KTO
,T1.COD_CONTRATTO_SAL
,T1.COD_RIFER_ANNO
,T1.COD_RIFER_MESE
,T1.COD_RIFER_ANNO || T1.COD_RIFER_MESE AS COD_RIFER
,T1.COD_CONTB_ETR
,T1.DAT_EST
,T1.DAT_ACC
,T1.DAT_SCA
,T1.COD_PAESE_UIC_NPE
FROM ES777A.VA_ES_DB_ANAGR_CONTO AS T1,
ES777A.VE_BFD_PDC AS T2
WHERE T1.TMS_INIZIO_VALIDITA <= T2.TMS_PDC
AND T1.TMS_FINE_VALIDITA > T2.TMS_PDC
AND T1.TMS_CANC_FISICA IS NULL
AND T1.FLG_RIFACIMENTO = 0
AND T1.COD_ABI = T2.COD_ABI
AND T2.NOM_VISTA='VA_ES_DB_ANAGR_CONTO'
AND T2.NUM_PERIO_RIF = 20200131
AND T2.COD_PERIODICITA = 'G'
AND T1.COD_PRODT_SALDO NOT IN ('1398' , '1698')
AND T1.COD_PRODT_SALDO IN ('1801', '1803', '1901', '1903', '3301', '3304', '3311', '3401', '3411', '3421')
)
AS T2
INNER JOIN
(
SELECT
T1.COD_ABI,
'00753'||T1.COD_PRODT_SALDO||T1.COD_CNTRT_SALDO AS COD_KTO,
Max(T1.COD_RIFER_ANNO || COD_RIFER_MESE) AS MAX_COD_RIFER
FROM ES777A.VA_ES_DB_ANAGR_CONTO AS T1,
ES777A.VE_BFD_PDC AS T2
WHERE
T1.TMS_INIZIO_VALIDITA <= T2.TMS_PDC
AND T1.TMS_FINE_VALIDITA > T2.TMS_PDC
AND T1.TMS_CANC_FISICA IS NULL
AND T1.FLG_RIFACIMENTO = 0
AND T1.COD_ABI = T2.COD_ABI
AND T2.NOM_VISTA = 'VA_ES_DB_ANAGR_CONTO'
AND T2.NUM_PERIO_RIF = 20200131
AND T2.COD_PERIODICITA = 'G'
AND T1.COD_PRODT_SALDO NOT IN ('1398' , '1698')
AND T1.COD_PRODT_SALDO IN ('1801', '1803', '1901', '1903', '3301', '3304', '3311', '3401', '3411', '3421')
GROUP BY T1.COD_PRODT_SALDO,T1.COD_ABI,T1.COD_CNTRT_SALDO
)
AS T1
ON ( T2.COD_ABI = T1.COD_ABI AND T2.COD_KTO = T1.COD_KTO AND T2.COD_RIFER = T1.MAX_COD_RIFER )
WHERE
( T2.DAT_EST > '2019-11-02' OR T2.DAT_EST IS NULL ) -- -90GG
AND ( T2.DAT_SCA > '2019-11-02' OR T2.DAT_SCA IS NULL ) -- -90GG
)
A
)
B
WHERE b.cc =
WHEN (B.CC > 1 AND B.DAT_EST IS NOT NULL) THEN 1
WHEN (B.CC > 1 AND B.DAT_EST IS NULL) THEN 0
WHEN (B.CC = 1) THEN 1 ELSE 0
END

Answer 1

This answers the original version of the question.
In Teradata, you can simplify the logic to:
SELECT ...,
Count(A.COD_ABI) Over (PARTITION BY A.COD_ABI, A.COD_KTO) AS CC
FROM A
QUALIFY CC > 1 AND DATE_EST IS NOT NULL;
All the subqueries are unnecessary