使用前に十分にテストしてください。私はそれをテストしましたが、これまでのところ良さそうに見えますが、徹底的なテストは行っていません。必要に応じてさらにテストして、結果に異常がある場合はそれを指摘したり、必要に応じて変更したりできれば、素晴らしいことです。
--Test data:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Prescriptions](
[PatientID] [int] NULL,
[StartDate] [datetime] NULL,
[EndDate] [datetime] NULL,
[Drug] [varchar](50) NULL,
[DrugCategory] [varchar](50) NULL
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13A00000000 AS DateTime), CAST(0x0000A13E00000000 AS DateTime), N'D', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13A00000000 AS DateTime), CAST(0x0000A13B00000000 AS DateTime), N'E', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13800000000 AS DateTime), CAST(0x0000A13B00000000 AS DateTime), N'F', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13800000000 AS DateTime), CAST(0x0000A13900000000 AS DateTime), N'G', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A12300000000 AS DateTime), CAST(0x0000A13900000000 AS DateTime), N'Z', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A12300000000 AS DateTime), CAST(0x0000A13A00000000 AS DateTime), N'Y', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13900000000 AS DateTime), CAST(0x0000A13D00000000 AS DateTime), N'A', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A13900000000 AS DateTime), CAST(0x0000A13C00000000 AS DateTime), N'B', N'Cat1')
INSERT [dbo].[Prescriptions] ([PatientID], [StartDate], [EndDate], [Drug], [DrugCategory]) VALUES (1, CAST(0x0000A14200000000 AS DateTime), CAST(0x0000A14400000000 AS DateTime), N'C', N'Cat1')
使用したクエリ:
SELECT DISTINCT PatientID,StartDate,EndDate,Drug,DrugCategory FROM (
SELECT
DATEDIFF(dd,a.startdate,b.startdate) c1
,DATEDIFF(dd,a.enddate,b.enddate)c2
,DATEDIFF(dd,a.startdate,b.enddate) c3
,DATEDIFF(dd,a.enddate,b.startdate) c4
,DATEDIFF(dd,a.startdate,b.enddate)+DATEDIFF(dd,a.enddate,b.startdate) c34
,a.PatientID
,a.StartDate
,a.EndDate
,a.Drug
,a.DrugCategory
,b.PatientID AS PatientID1
,b.StartDate AS StartDate1
,b.EndDate AS EndDate1
,b.Drug AS Drug1
,b.DrugCategory DrugCategory1
FROM Prescriptions a
,Prescriptions b
WHERE a.patientid=b.patientid
AND a.DrugCategory= b.DrugCategory
and a.drug<>b.drug
)a
WHERE c1*c2*c3*c4 <0
AND c3>2
and c4<=-2
ORDER BY 1,2,3,4
結果:
PatientID StartDate EndDate Drug DrugCategory
----------- ----------------------- ----------------------- -------------------------------------------------- --------------------------------------------------
1 2012-12-10 00:00:00.000 2013-01-02 00:00:00.000 Y Cat1
1 2012-12-31 00:00:00.000 2013-01-03 00:00:00.000 F Cat1
1 2013-01-01 00:00:00.000 2013-01-04 00:00:00.000 B Cat1
1 2013-01-01 00:00:00.000 2013-01-05 00:00:00.000 A Cat1
1 2013-01-02 00:00:00.000 2013-01-06 00:00:00.000 D Cat1
(5 row(s) affected)