在 SQL 查询中折叠/合并列

Question

我有一个如下所示的表格：

如何从该表中进行选择，以便将多个子代码列转换为行？不确定这是否是 PIVOT 问题。请指教。

所需的样本输出：

附件是带有数据插入脚本的 SQL 供您参考。

    USE [TEST]
GO
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[SubCodeReport](
    [ S-ID] [varchar](50) NULL,
    [AGE] [varchar](50) NULL,
    [SchoolCode] [varchar](50) NULL,
    [SubCode] [varchar](50) NULL
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[SubCodeReport3]    Script Date: 9/8/2015 6:05:30 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[SubCodeReport3](
    [ S-ID] [varchar](50) NULL,
    [AGE] [varchar](50) NULL,
    [SchoolCode] [varchar](50) NULL,
    [SubCode1] [varchar](50) NULL,
    [SubCode2] [varchar](50) NULL,
    [SubCode3] [varchar](50) NULL,
    [SubCode4] [varchar](50) NULL,
    [SubCode5] [varchar](50) NULL
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'25', N'23', N'KEN-009', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'26', N'21', N'DLK-009', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'27', N'25', N'DLK-006', N'MAT')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'27', N'25', N'DLK-006', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'27', N'25', N'DLK-006', N'STAT')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'28', N'21', N'HLI-005', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'29', N'22', N'NUI-002', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'29', N'22', N'NUI-002', N'MAT')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'30', N'22', N'INN-009', N'ENG')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'30', N'22', N'INN-009', N'MAT')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'30', N'22', N'INN-009', N'ZOO')
INSERT [dbo].[SubCodeReport] ([ S-ID], [AGE], [SchoolCode], [SubCode]) VALUES (N'30', N'22', N'INN-009', N'GEO')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'25', N'23', N'KEN-009', N'ENG', N'', N'', N'', N'')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'26', N'21', N'DLK-009', N'ENG', N'', N'', N'', N'')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'27', N'25', N'DLK-006', N'MAT', N'ENG', N'STAT', N'', N'')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'28', N'21', N'HLI-005', N'ENG', N'', N'', N'', N'')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'29', N'22', N'NUI-002', N'ENG', N'MAT', N'', N'', N'')
INSERT [dbo].[SubCodeReport3] ([ S-ID], [AGE], [SchoolCode], [SubCode1], [SubCode2], [SubCode3], [SubCode4], [SubCode5]) VALUES (N'30', N'22', N'INN-009', N'ENG', N'MAT', N'ZOO', N'GEO', N'')

Answer 1

您可以使用unpivot 来获得想要的结果。

Fiddle with sample data from the question

select [ S-ID], age, schoolcode, u.subcode
from subcodereport3
unpivot 
(subcode 
for x in (subcode1,subcode2,subcode3,subcode4,subcode5) ) u
where u.subcode <> ' '