SQL Server在nvarchar列上创建聚簇索引，强制排序

Question

I want have a small table with two columns [Id] [bigint] and [Name] [nvarchar](63) . The column is used for tags and it will contain all tags that exist. I want to force an alphabetical sorting by the Name column so that a given tag is found more quickly.

Necessary points are:

1. The Id is my primary key, I use it eg for foreign keys.
2. The Name is unique as well.
3. I want to sort by Name alphabetically.
4. I need the SQL command for creating the constraints since I use scripts to create the table.

I know you can sort the table by using a clustered index, but I know that the table is not necessarily in that order.

My query looks like this but I don't understand how to create the clustered index on Name but still keep the Id as Primary Key:

IF NOT EXISTS (SELECT * FROM sys.objects 
               WHERE object_id = OBJECT_ID(N'[dbo].[Tags]') 
                 AND type in (N'U'))
BEGIN
    CREATE TABLE [dbo].[Tags] 
    (
        [Id] [bigint] IDENTITY(1,1) PRIMARY KEY NOT NULL,
        [Name]  [nvarchar](63) NOT NULL,

        CONSTRAINT AK_TagName UNIQUE(Name)
    )
END

Edit:

I decided to follow paparazzo's advice. So if you have the same problem make sure you read his answer as well.

Answer 1

You should NOT do what you want to do.

Let the Id identity be the clustered PK. It (under normal use) will not fragment.

A table has no natural order. You have to sort by to get an order. Yes data is typically presented in PK order but that is just a convenience the query optimizer may or may not use.

Just put a non clustered unique index on Name and sort by it in the select .

You really need bigint? That is a massive table.

Answer 2

You can specify that the Primary Key is NONCLUSTERED when declaring it as a constraint, you can then declare the Unique Key as being the CLUSTERED index.

CREATE TABLE [dbo].[Tags] (
    [Id]    [bigint] IDENTITY(1,1) NOT NULL,
    [Name]  [nvarchar](63) NOT NULL,
    CONSTRAINT PK_Tag PRIMARY KEY NONCLUSTERED (Id ASC),
    CONSTRAINT AK_TagName UNIQUE CLUSTERED (Name ASC)
);

Also specifying ASC or DESC after the Column name (within the key/index declaration) sets the index sort order. The default is usually ascending.