MS SQL Server Concepts and Programming Question:
Download Questions PDF

Is the PRIMARY KEY Column of a Table an Index in MS SQL Server?

Answer:

If you define a primary key on a table, an index for the primary key column will be created by default. The tutorial exercise below shows you the index created as part of the primary key column of "ggl_links":

USE GlobalGuideLineDatabase;
GO

-- Drop the old table, if needed
DROP TABLE ggl_links;
GO

-- Create a table with primary key
CREATE TABLE ggl_links (
id INT PRIMARY KEY,
url VARCHAR(80) NOT NULL,
notes VARCHAR(1024),
counts INT,
created DATETIME NOT NULL DEFAULT(getdate())
);
GO

-- Create an index for column "url"
CREATE INDEX ggl_links_url ON ggl_links (url);
GO

-- View indexes
EXEC SP_HELP ggl_links;
GO
index_name               index_description           keys
----------------------- -------------------------- ----
ggl_links_url nonclustered located url
on PRIMARY

PK__ggl_links__239E4DCF clustered, unique, primary
key located on PRIMARY id

Notice that the index created as part of the primary key is named by SQL Server as "PK__ggl_links__239E4DCF".

Download MS SQL Server Interview Questions And Answers PDF

Previous QuestionNext Question
How To Drop Existing Indexes in MS SQL Server?Does the UNIQUE Constraint Create an Index?