求一个SQL查询 - MS-SQL Server / 应用实例

表A
字段a 字段b
01 a
02 b
03 c
04 d

表B
字段a 字段c 字段X  
01 a001 1
01 a002 2
01 a003 3
02 b001 1
02 b002 2
02 b003 3
03 c001 1
03 c002 2
03 c003 3
04 d001 1
04 d002 2
04 d003 3

求查询结果为
01 a a001 a002 a003
02 b b001 b002 b003
03 c c001 c002 c003
04 d d001 d002 d003

sql 查询代码如何写 谢谢~

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字段X 固定是3个吗？

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select a.*,
  max(case b.x when 1 then b.c else '' end) [1],
  max(case b.x when 2 then b.c else '' end) [2],
  max(case b.x when 3 then b.c else '' end) [3]
from a , b
where a.a = b.a 
group by a.a a.b

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select a.*,
  max(case b.x when 1 then b.c else '' end) [1],
  max(case b.x when 2 then b.c else '' end) [2],
  max(case b.x when 3 then b.c else '' end) [3]
from a , b
where a.a = b.a 
group by a.a ,a.b

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SQL code:
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-- Author : htl258(Tony)
-- Date : 2010-05-19 15:50:56
-- Version: Microsoft SQL Server 2008 (RTM) -