Using IF in SQL Function with 2 Table - sql

Question

I have a page like this
Baş Tar. --> Start Date
Bit. Tar --> End Date
I have a SQL like this for this page,
SELECT B.HESAP_NO, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2 AS 'TEKLIF',B.MUS_K_ISIM,
dbo.fngcodeme(B.HESAP_NO, B.DOVIZ_KOD, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2,'01/01/2011', '11/03/2011') AS 'YATAN',
(CASE WHEN B.DOVIZ_KOD = 21 THEN 'EUR' WHEN B.DOVIZ_KOD = 2 THEN 'USD' WHEN B.DOVIZ_KOD = 1 THEN 'TL' END) AS 'KUR',
D.AVUKAT,
(CASE WHEN D.HESAP IN (SELECT T_HESAP_NO FROM TAKIP) THEN
(SELECT CONVERT(VARCHAR(10),ICRA_TAR,103) FROM TAKIP WHERE T_HESAP_NO = D.HESAP)
ELSE ' ' END) AS 'ICRA TARİHİ',
(CASE WHEN D.HESAP IN (SELECT T_HESAP_NO FROM TAKIP) THEN
(SELECT CONVERT(VARCHAR(10),HACIZ_TAR,103) FROM TAKIP WHERE T_HESAP_NO = D.HESAP)
ELSE '' END) AS 'HACİZ TARİHİ'
FROM YAZ..MARDATA.S_TEKLIF B, AVUKAT D
WHERE B.HESAP_NO = D.HESAP
AND B.KAPANIS_TAR IS NULL
AND ISNULL(dbo.fngcodeme(B.HESAP_NO, B.DOVIZ_KOD, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2,'01/01/2011', '11/03/2011'),0) > 0
GROUP BY B.HESAP_NO, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2,B.DOVIZ_KOD ,B.MUS_K_ISIM, D.AVUKAT, D.HESAP
And this is my dbo.fngcodeme Function,
ALTER FUNCTION [dbo].[fngcodeme]
(
#HESAP INT, #DOV INT, #TEKLIF VARCHAR(10), #BAS VARCHAR(10), #BIT VARCHAR(10)
)
RETURNS FLOAT
AS
BEGIN
DECLARE #Result FLOAT
SET #Result = (SELECT SUM(TUTAR)
FROM YAZ..MARDATA.M_GHAREKET
WHERE TEMEL_HESAP = #HESAP
AND DOVIZ_KOD = #DOV
AND REF_KOD = 'GC'
AND BACAK_GRUP = 'PERT'
AND ISL_KOD = 1
AND ACIKLAMA LIKE '%' + #TEKLIF + '%'
AND ISL_TAR >= CONVERT(DATETIME, + '' + #BAS + '',103)
AND ISL_TAR <= CONVERT(DATETIME, + '' + #BIT + '',103)
)
RETURN #Result
END
What i want is
IF `Bit. Tar. (End Date)` is less or equal then 28/02/2011 --> Use M_HAREKET(table)
IF Baş. Tar. (Start Date) is great or equal then 01/03/2011 --> Use M_GHAREKET(table)
How can i do that?
Should i change SQL or Function? Which one?

Answer 1

If #BAS and #BIT are dates, pass them in as dates. Don't use VARCHAR.
ALTER FUNCTION [dbo].[fngcodeme]
(
#HESAP INT, #DOV INT, #TEKLIF VARCHAR(10), #BAS datetime, #BIT datetime
)
RETURNS FLOAT
AS
BEGIN
DECLARE #Result FLOAT
IF CONVERT(DATETIME, #BIT,103) <= '20110228'
SET #Result = (SELECT SUM(TUTAR)
FROM YAZ..MARDATA.M_HAREKET
WHERE TEMEL_HESAP = #HESAP
AND DOVIZ_KOD = #DOV
AND REF_KOD = 'GC'
AND BACAK_GRUP = 'PERT'
AND ISL_KOD = 1
AND ACIKLAMA LIKE '%' + #TEKLIF + '%'
AND ISL_TAR >= CONVERT(DATETIME, #BAS,103)
AND ISL_TAR <= CONVERT(DATETIME, #BIT,103)
)
ELSE
SET #Result = (SELECT SUM(TUTAR)
FROM YAZ..MARDATA.M_GHAREKET
WHERE TEMEL_HESAP = #HESAP
AND DOVIZ_KOD = #DOV
AND REF_KOD = 'GC'
AND BACAK_GRUP = 'PERT'
AND ISL_KOD = 1
AND ACIKLAMA LIKE '%' + #TEKLIF + '%'
AND ISL_TAR >= CONVERT(DATETIME, #BAS,103)
AND ISL_TAR <= CONVERT(DATETIME, #BIT,103)
)
RETURN #Result
END
As for the calling function, don't use region specific date formats. Stick to YYYYMMDD or one of the ISO/XML ones. So your query would be
SELECT B.HESAP_NO, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2 AS 'TEKLIF',B.MUS_K_ISIM,
dbo.fngcodeme(B.HESAP_NO, B.DOVIZ_KOD, B.TEKLIF_NO1 + '/' + B.TEKLIF_NO2,'20110101', '20110311') AS 'YATAN',
......