SQL中动态进行行转列

课程表

CREATE TABLE [dbo].[demo_Course](
    [Cid] [uniqueidentifier] NOT NULL,
    [CourseName] [varchar](50) NULL,
 CONSTRAINT [PK_demo_Course] PRIMARY KEY CLUSTERED 
(
    [Cid] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

学员表

CREATE TABLE [dbo].[demo_Student](
    [Sid] [uniqueidentifier] NOT NULL,
    [Pid] [uniqueidentifier] NULL,
    [StudentName] [varchar](50) NULL,
    [JoinDate] [datetime] NULL,
    [Sex] [int] NULL,
    [Old] [int] NULL,
 CONSTRAINT [PK_demo_Student] PRIMARY KEY CLUSTERED 
(
    [Sid] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

成绩表

CREATE TABLE [dbo].[demo_Score](
    [Sid] [uniqueidentifier] NOT NULL,
    [Cid] [uniqueidentifier] NOT NULL,
    [Score] [int] NOT NULL
) ON [PRIMARY]

行转列

Declare @sql varchar(8000)
Set @sql = 'Select Sid'
Select @sql = @sql + ',max(case CourseName when '''+CourseName+''' then Score else 0 end) ['+CourseName+']'
from demo_Course as cj  --把所有唯一的科目的名称都列举出来
Select @sql = @sql+' from (select s.sid , c.CourseName , s.Score from demo_Course c left join demo_Score s on c.Cid = s.Cid) t group by Sid'
print (@sql)

上面这段输出的SQL如下：

Select Sid,max(case CourseName when '数学' then Score else 0 end) [数学],
max(case CourseName when '英语' then Score else 0 end) [英语],
max(case CourseName when '语文' then Score else 0 end) [语文] from 
(select s.sid , c.CourseName , s.Score from demo_Course c left join demo_Score s on c.Cid = s.Cid) t group by Sid