--> 测试数据：[Permission]
if object_id('[Permission]') is not null drop table [Permission]
create table [Permission]([PID] varchar(4),[PName] varchar(4))
insert [Permission]
select 'P001','读取' union all
select 'P002','追加' union all
select 'P003','删除'

--> 测试数据：[USER]
if object_id('[USER]') is not null drop table [USER]
create table [USER]([USERID] varchar(4),[USERNAME] varchar(6))
insert [USER]
select 'U001','赵用户' union all
select 'U002','钱用户' union all
select 'U003','孙用户'

--> 测试数据：[PerAssign]
if object_id('[PerAssign]') is not null drop table [PerAssign]
create table [PerAssign]([PID] varchar(4),[USERID] varchar(4))
insert [PerAssign]
select 'P001','U001' union all
select 'P001','U002' union all
select 'P001','U003' union all
select 'P002','U002' union all
select 'P002','U003' union all
select 'P003','U002'

SELECT C.USERID AS 用户ID,C.USERNAME AS 用户名,
C.PID AS 权限ID,C.PName AS 权限名,
CASE WHEN D.PName IS NULL THEN '否' ELSE '是'END AS 是否有权限 
FROM(SELECT * FROM [USER] CROSS JOIN [Permission])C
LEFT JOIN(SELECT A.PID,A.USERID,B.PName FROM [PerAssign] A 
LEFT JOIN [Permission] B ON A.PID=B.PID)D ON C.USERID=D.USERID 
AND C.PID=D.PID


 /*
 用户ID    用户名    权限ID    权限名    是否有权限
U001    赵用户    P001    读取    是
U001    赵用户    P002    追加    否
U001    赵用户    P003    删除    否
U002    钱用户    P001    读取    是
U002    钱用户    P002    追加    是
U002    钱用户    P003    删除    是
U003    孙用户    P001    读取    是
U003    孙用户    P002    追加    是
U003    孙用户    P003    删除    否
*/