sql - 如何在 SQL Server 中的表类型上创建过滤索引？

Question

CREATE TYPE [dbo].[MyTableType] AS TABLE
(
    Id INT NULL INDEX ix UNIQUE WHERE Id IS NOT NULL /*Unique ignoring nulls*/
    , Sort INT NOT NULL
    , [Name] NVARCHAR(MAX) NULL 
)

SQL Server 2016 中执行此操作的新方法是什么？我一直遇到以下错误

Incorrect syntax near 'INDEX'. If this is intended as a part of a table hint, a WITH keyword and parenthesis are now required. See SQL Server Books Online for proper syntax.

Answer 1

从此Microsoft Article :

A nonclustered index cannot be created on a user-defined table type unless the index is the result of creating a PRIMARY KEY or UNIQUE constraint on the user-defined table type. (SQL Server enforces any UNIQUE or PRIMARY KEY constraint by using an index.)

我认为为表类型创建唯一索引的唯一方法是:

CREATE TYPE [dbo].[MyTableType] AS TABLE
(
    Id INT NULL UNIQUE
    , Sort INT NOT NULL
    , [Name] NVARCHAR(MAX) NULL 
)

我认为您不能添加类似于以下内容的“忽略 NULLS”选项:

CREATE UNIQUE NONCLUSTERED INDEX idx_yourcolumn_notnull
ON YourTable(yourcolumn)
WHERE yourcolumn IS NOT NULL;