Matrix result using SQL Server 2008 R2

问题

I have a table as shown below:

Example:

CREATE TABLE matrix
(
  a VARCHAR(10),
  b VARCHAR(10)
);

INSERT INTO matrix VALUES('A','H')
INSERT INTO matrix VALUES('B','I')
INSERT INTO matrix VALUES('C','J')
INSERT INTO matrix VALUES('D','K')
INSERT INTO matrix VALUES('E','L')
INSERT INTO matrix VALUES('F','M')
INSERT INTO matrix VALUES('G','N')
INSERT INTO matrix VALUES('A','M')

SELECT * FROM matrix;

Looks like:

a    b
-------
A    H
B    I
C    J
D    K
E    L
F    M
G    N
A    M

Now I want to show the result in the following matrix format:

Expected Result:

     H    I    J    K    L    M    N
 --------------------------------------
 A | 1    0    0    0    0    1    0
   | 
 B | 0    1    0    0    0    0    0
   |
 C | 0    0    1    0    0    0    0
   |
 D | 0    0    0    1    0    0    0
   |
 E | 0    0    0    0    1    0    0
   |
 F | 0    0    0    0    0    1    0
   |
 G | 0    0    0    0    0    0    1

回答1:

DECLARE @DynamicPivotQuery AS NVARCHAR(max)   
DECLARE @ColumnName AS NVARCHAR(max)   
DECLARE @ColumnName1 AS NVARCHAR(max) 

SELECT  @ColumnName = Isnull(@ColumnName+',', '') + b,         
        @ColumnName1 = Isnull(@ColumnName1+',', '') + 'isnull(' + b + ',0)' + ' as ' + b  
FROM   (    SELECT DISTINCT b   FROM   matrix)  AS   qry1

--Select @ColumnName,@ColumnName1  
SET @DynamicPivotQuery =      
' Select ' + @ColumnName1 + '    
from  (Select *,1 ''VALUE''  from matrix ) as t pivot  ( Sum(VALUE ) for b in (' +  @ColumnName      + '))   
as pvt ' 

--print @DynamicPivotQuery  
EXEC Sp_executesql  @DynamicPivotQuery 

来源：https://stackoverflow.com/questions/25932321/matrix-result-using-sql-server-2008-r2