How can I insert IF in where cluase? (TSQL) - tsql

Question

I have this query in TSQL
DECLARE #DATA_INIZIO AS DATE
DECLARE #DATA_FINE AS DATE
SELECT 'TEMPERATURA RILEVATA', VS.EffectiveTimeMin as ORA, CAST(VS.Value AS INT), row_number() over (order by VS.EffectiveTimeMin) AS CONTEGGIO
FROM AA_V_PHR_CCD_VitalSigns V INNER JOIN AA_V_PHR_CCD_VitalSignsXResults VS ON V.ID = VS.IDVitalSigns
WHERE V.IDResultTypeValueSet = 23 AND V.IDClinicalDocument = 46
ORDER BY VS.EffectiveTimeMin asc
But, I want to add this condiTIon at the where clause:
IF(#Data_Inizio is not null and #Data_Fine is not null)
v.effectivetime between #data_inizio and #data_fine
how can I do this?

Answer 1

(
(#Data_Inizio is not null and #Data_Fine is not null)
AND
v.effectivetime between #data_inizio and #data_fine
)
Should be fine if I understood you properly.
Hmm maybe you don't have properly values, or your dates are incorrect, look at my sample below:
DECLARE #DATA_INIZIO AS DATE = '2017/01/01'
DECLARE #DATA_FINE AS DATE = '2017/02/01'
Declare #Tmp Table
(
IdResult Int, IdClinical Int, EffectiveTime DateTime
)
Insert Into #Tmp (IdResult, IdClinical, EffectiveTime)
Values
(23, 46, '2017/01/23'), (22, 46, '2017/01/23'),
(23, 46, '2017/01/2'), (23, 47, '2017/01/23'),
(23, 46, '2017/01/5'), (23, 46, '2017/02/23')
SELECT *
FROM
#Tmp V
WHERE
V.IdResult = 23 AND V.IdClinical = 46
AND
(
(#Data_Inizio is null OR #Data_Fine is null)
OR
v.effectivetime between #data_inizio and #data_fine
)

Answer 2

try to add those lines in your WHERE clause:
SELECT
'TEMPERATURA RILEVATA',
VS.EffectiveTimeMin as ORA,
CAST(VS.Value AS INT),
row_number() over (order by VS.EffectiveTimeMin) AS CONTEGGIO
FROM
AA_V_PHR_CCD_VitalSigns V
INNER JOIN AA_V_PHR_CCD_VitalSignsXResults VS
ON V.ID = VS.IDVitalSigns
WHERE
V.IDResultTypeValueSet = 23
AND V.IDClinicalDocument = 46
AND ( (#DATA_INIZIO is null OR #DATA_FINE is null)
OR -- when both are not null
(#DATA_INIZIO <= v.effectivetime AND v.effectivetime <= #DATA_FINE)
)
ORDER BY VS.EffectiveTimeMin ASC
you can 'translate' your IF statement to sth like:
when DATA_INIZIO or DATA_FINE is not set (null) then return record
when they are both set - check if v.effectivetime fits their range