Question

我在SQL Server 2005中有以下表模式，我想将其反规范化为我正在编写的一些查询的索引视图，直到我可以使结构更改成为永久性。

表格如下

Writing
(
DocumentSerial int
Grader1_ID int
Grade_1 int
Grader2_ID int 
Grade_2 int 
Grader3_ID int 
Grade_3 int
)

Users
(userID int,
firstname,
lastname
)

我想为每个评分者/成绩/文件组合提供一个单行的表格，其中评分者是评分者1，评分者2或评分者3

我编写的View使用UNION，因此它不会索引：

select documentSerial,grader1_id as grader_id, grade_1 as grade ,1 as sequence
 from Writing w inner join User U on w.grader1_id=u.userid
UNION
select documentSerial,grader2_id as grader_id, grade_2 as grade ,2 as sequence
 from Writing w inner join User U on w.grader2_id=u.userid
UNION
select documentSerial,grade31_id as grader_id, grade_3 as grade ,3 as sequence
 from Writing w inner join User U on w.grader3_id=u.userid

问题是 - SQL无法使用union索引视图...

Answer 1

为什么在使用正确的表时必须是索引视图：

SELECT x.*
  INTO normalized_table
  FROM (select documentSerial,grader1_id as grader_id, grade_1 as grade ,1 as sequence
          from Writing w 
          join User U on w.grader1_id = u.userid
        UNION ALL
        select documentSerial,grader2_id as grader_id, grade_2 as grade ,2 as sequence
          from Writing w 
          join User U on w.grader2_id = u.userid
        UNION ALL
        select documentSerial,grade31_id as grader_id, grade_3 as grade ,3 as sequence
          from Writing w 
          join User U on w.grader3_id = u.userid) x

我知道你可能想要这个视图，所以你没有同步数据的麻烦。唯一的另一种选择是不对视图编制索引......

模拟联合以制作索引视图

1 个答案: