Проблема с запросом SQL Server

Question

У меня есть проблема с этим запросом. Я хочу получить последнюю кандидатуру (см. Ниже запрос). Результат должен быть такой:

aId Position    Startdate  Enddate  

154 Web Developer   2008-04-07  NULL 
155 Analyst    2008-06-12  2009-06-12 
156 Quality Controller  2001-08-01  2010-01-01 
165 Programmer    1995-08-02  2010-01-01 
166 Programmer    2001-01-14  2010-01-14 
170 Web Developer   2010-03-17  NULL 
168 Business Analyst  2010-05-10  NULL 

но запрос ниже дался мне результат, как этот

aId Position      Startdate     Enddate  

154 Lead Software Developer 2007-04-07 00:00:00.000 2008-04-07 00:00:00.000 
154 Web Developer 2008-04-07 00:00:00.000 NULL 
155 Analyst 2008-06-12 00:00:00.000 2009-06-12 00:00:00.000 
156 Quality Controller 2001-08-01 00:00:00.000 2010-01-01 00:00:00.000 
165 Programmer 1995-08-02 00:00:00.000 2010-01-01 00:00:00.000 
166 Programmer 2001-01-14 00:00:00.000 2010-01-14 00:00:00.000 
170 Web Developer 2010-03-17 00:00:00.000 NULL 
168 Business Analyst 2010-05-10 00:00:00.000 NULL 
168 Analyst Programmer 2010-05-03 00:00:00.000 2010-05-10 00:00:00.000 

запрос не должен повторять данные, имеющие тот же Aid, какие недостающие с этим запрос ниже?

SELECT 
    aId 
    , Position 
    , StartDate 
    , Enddate 
FROM EmploymentDetails ed 
WHERE 
    ((Enddate IS NULL) OR 
    (Enddate = (SELECT MAX(Enddate) 
       FROM EmploymentDetails edin 
       WHERE edin.aId = ed.aId))) 




    create table EmploymentDetails(
    Id     bigint   not null identity constraint PK_EmploymentDetails primary key, 
    aId     bigint   not null, 
    Startdate   datetime, 
    Enddate    datetime, 
    Position   varchar(30), 
    PositionLevelId  bigint   not null, 
    SpecializationId bigint   not null, 
    PositionId   bigint   not null, 
    StartSalary   varchar(50), 
    EndSalary   varchar(50), 
    DescriptionofDuties nvarchar(1000), 
    ReasonforLeaving nvarchar(200), 
    CompanyName   nvarchar(100), 
    TypeofBusiness  varchar(50), 
    Address1   varchar(25), 
    Address2   varchar(25), 
    City    varchar(25), 
    Province   varchar(25), 
    StateorRegion  varchar(25), 
    CountryId   bigint, 
    PostalCode   varchar(10) 
) 
go 






    INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (34, 154, CAST(0x0000962900000000 AS DateTime), CAST(0x0000979F00000000 AS DateTime), N'Sr. .Net Developer', 4, 1, 1, N'P12,000', N'P12,000', N'Design websites for company using Adobe dreamweaver, Flash and other web applications.', N'sample reason for leaving', N'Appsource', N'Information Technology', N'Unit 1401 Robinsons Equit', N'ADB Ave. Corner Poveda Ro', N'Pasig', N'NCR', N'NCR', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (35, 154, CAST(0x0000990900000000 AS DateTime), CAST(0x00009A7700000000 AS DateTime), N'Lead Software Developer', 4, 2, 1, N'P12,000', N'P12,000', N'Design websites for company using Adobe dreamweaver, Flash and other web applications.', N'sample reason for leaving', N'Corebuilt Technologies', N'Information Technology', N'24/F 88 Corporate Center', N'Valero St.,', N'Makati', N'NCr', N'NCr', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (36, 154, CAST(0x00009A7700000000 AS DateTime), NULL, N'Web Developer', 4, 1, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'IDCSI', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', N'', N'NCR', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (38, 155, CAST(0x00009AB900000000 AS DateTime), CAST(0x00009C2600000000 AS DateTime), N'Analyst', 4, 3, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'IDCSI', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', NULL, NULL, 177, NULL) 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (40, 156, CAST(0x000090EE00000000 AS DateTime), CAST(0x00009CF100000000 AS DateTime), N'Quality Controller', 4, 2, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'IDCSI', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', N'', N'', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (41, 165, CAST(0x0000722E00000000 AS DateTime), CAST(0x0000882800000000 AS DateTime), N'Analyst', 4, 2, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'Microsoft', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', NULL, NULL, 177, NULL) 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (42, 165, CAST(0x0000885F00000000 AS DateTime), CAST(0x00009CF100000000 AS DateTime), N'Programmer', 4, 3, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'Microsoft', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', N'', N'', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (44, 166, CAST(0x0000902700000000 AS DateTime), CAST(0x00009CFE00000000 AS DateTime), N'Programmer', 4, 1, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'Microsoft', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', NULL, NULL, 177, NULL) 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (45, 168, CAST(0x0000887E00000000 AS DateTime), CAST(0x00009B0B00000000 AS DateTime), N'Analyst', 4, 2, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'Microsoft', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', NULL, NULL, 177, NULL) 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (47, 170, CAST(0x00009D3C00000000 AS DateTime), NULL, N'Web Developer', 4, 2, 1, N'P15,000', N'P15,000', N'sample description', N'sample description', N'Microsoft', N'Information Technology', N'15/F Summit One Tower', N'530 Shaw Blvd.,', N'Mandaluyong', NULL, NULL, 177, NULL) 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (48, 156, CAST(0x00009A7300000000 AS DateTime), CAST(0x00009BE500000000 AS DateTime), N'', 4, 2, 1, N'P34,343', N'P3,434', N'fgf', N'fgfggf', N'fgfg', N'Information Technology', N'fgfg', N'fgfg', N'fgfg', N'fgfgf', N'fgfg', 177, N'4545') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (49, 156, CAST(0x00009BDF00000000 AS DateTime), CAST(0x00009C4700000000 AS DateTime), N'', 4, 1, 1, N'P343', N'P344,343', N'dfdf', N'dfdf', N'dfdfd', N'Information Technology', N'ff', N'', N'dffd', N'', N'', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (51, 168, CAST(0x00009D7200000000 AS DateTime), NULL, N'Business Analyst', 4, 1, 1, N'P3,434', N'P33,333', N'3434', N'3434', N'dsd', N'Information Technology', N'sdsds', N'', N'sdsd', N'', N'', 177, N'') 
INSERT [dbo].[EmploymentDetails] ([Id], [aId], [Startdate], [Enddate], [Position], [PositionLevelId], [SpecializationId], [PositionId], [StartSalary], [EndSalary], [DescriptionofDuties], [ReasonforLeaving], [CompanyName], [TypeofBusiness], [Address1], [Address2], [City], [Province], [StateorRegion], [CountryId], [PostalCode]) VALUES (52, 168, CAST(0x00009D6B00000000 AS DateTime), CAST(0x00009D7200000000 AS DateTime), N'Analyst Programmer', 4, 1, 1, N'P43,434', N'P434,343', N'4', N'344', N'3434', N'Information Technology', N'434', N'', N'3434', N'', N'', 177, N'') 

Answer 1

Предполагая, что SQL Server 2005+

WITH E AS 
(
SELECT 
    aId 
    , Position 
    , StartDate 
    , Enddate 
    ,ROW_NUMBER() OVER (PARTITION BY aId ORDER BY 
      CASE WHEN Enddate IS NULL THEN 0 ELSE 1 END ASC, 
      (CAST(Enddate as datetime)) DESC) AS RN 
FROM EmploymentDetails ed 
) 
LatestJob AS (SELECT aId, Position, StartDate, Enddate FROM E WHERE RN=1), 
EarliestStart AS (SELECT ... 

Кстати, почему вы хранящей даты как VARCHAR, а не date (SQL2008) или datetime? Редактировать Я вижу, что последний вопрос теперь задан в вопросе.