NEWID
Creates a unique value of type uniqueidentifier. 

Syntax
NEWID ( ) 

Return Types
uniqueidentifier

Examples
A. Use the NEWID function with a variable
This example uses NEWID to assign a value to a variable declared as the uniqueidentifier data type. The value of the uniqueidentifier data type variable is printed before the value is tested.

-- Creating a local variable with DECLARE/SET syntax.
DECLARE @myid uniqueidentifier
SET @myid = NEWID()
PRINT 'Value of @myid is: '+ CONVERT(varchar(255), @myid)

Here is the result set:

Value of @myid is: 6F9619FF-8B86-D011-B42D-00C04FC964FF



Note  The value returned by NEWID is different for each computer. This number is shown only for illustration.


B. Use NEWID in a CREATE TABLE statement
This example creates cust table with a uniqueidentifier data type, and uses NEWID to fill the table with a default value. In assigning the default value of NEWID(), each new and existing row has a unique value for the cust_id column. 

-- Creating a table using NEWID for uniqueidentifier data type. 
CREATE TABLE cust
(
 cust_id uniqueidentifier NOT NULL
   DEFAULT newid(),
 company varchar(30) NOT NULL,
 contact_name varchar(60) NOT NULL, 
 address varchar(30) NOT NULL, 
 city varchar(30) NOT NULL,
 state_province varchar(10) NULL,
 postal_code varchar(10) NOT NULL, 
 country varchar(20) NOT NULL, 
 telephone varchar(15) NOT NULL,
 fax varchar(15) NULL
)
GO
-- Inserting data into cust table.
INSERT cust
(cust_id, company, contact_name, address, city, state_province, 
 postal_code, country, telephone, fax)
VALUES
(newid(), 'Wartian Herkku', 'Pirkko Koskitalo', 'Torikatu 38', 'Oulu', NULL,
 '90110', 'Finland', '981-443655', '981-443655')
INSERT cust
(cust_id, company, contact_name, address, city, state_province,
postal_code, country, telephone, fax)
VALUES 
(newid(), 'Wellington Importadora', 'Paula Parente', 'Rua do Mercado, 12', 'Resende', 'SP',
 '08737-363', 'Brazil', '(14) 555-8122', '')
INSERT cust
(cust_id, company, contact_name, address, city, state_province,
 postal_code, country, telephone, fax)
VALUES
(newid(), 'Cactus Comidas para Ilevar', 'Patricio Simpson', 'Cerrito 333', 'Buenos Aires', NULL, 
 '1010', 'Argentina', '(1) 135-5555', '(1) 135-4892')
INSERT cust
(cust_id, company, contact_name, address, city, state_province,
 postal_code, country, telephone, fax)
VALUES 
(newid(), 'Ernst Handel', 'Roland Mendel', 'Kirchgasse 6', 'Graz', NULL,
 '8010', 'Austria', '7675-3425', '7675-3426')
INSERT cust
(cust_id, company, contact_name, address, city, state_province,
 postal_code, country, telephone, fax)
VALUES 
(newid(), 'Maison Dewey', 'Catherine Dewey', 'Rue Joseph-Bens 532', 'Bruxelles', NULL,
 'B-1180', 'Belgium', '(02) 201 24 67', '(02) 201 24 68')
GO

C. Use uniqueidentifier and variable assignment
This example declares a local variable called @myid as a variable of uniqueidentifier data type. Then, the variable is assigned a value using the SET statement.

DECLARE @myid uniqueidentifier 
SET @myid = 'A972C577-DFB0-064E-1189-0154C99310DAAC12'
GO


See Also 

ALTER TABLE

CAST and CONVERT

CREATE TABLE

Data Types

Replication Overview

System Functions

uniqueidentifier

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