如何在 SQL Server 中使用 NOT IN 创建过滤索引

Question

我想创建唯一的非聚集索引，它限制特定列的某些记录，我使用 NOT IN 来过滤它，但由于 NOT IN，我收到错误。有什么替代方法可以做到这一点？

CREATE UNIQUE NONCLUSTERED INDEX 
[UN_Student] ON [dbo].[Student]
(
[School_Cd] ASC,
[Class_Id] ASC,
[Enroll_Dt] ASC,
[Email_Id] ASC
)
WHERE ([School_Cd]='EM' AND [Class_Id] NOT IN (1,2,3))
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, 
IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = 
ON, ALLOW_PAGE_LOCKS = ON)

Answer 1

过滤索引不能使用NOT IN. 您可以改用多个AND运算符。Brent Ozar 有一篇非常好的文章，介绍了过滤索引允许和不允许的内容。

CREATE UNIQUE NONCLUSTERED INDEX 
[UN_Student] ON [dbo].[Student]
(
[School_Cd] ASC,
[Class_Id] ASC,
[Enroll_Dt] ASC,
[Email_Id] ASC
)
WHERE ([School_Cd]='EM' AND [Class_Id] <> 1 AND [Class_Id] <> 2 AND [Class_Id] <> 3)
WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, 
IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = 
ON, ALLOW_PAGE_LOCKS = ON)