SQL Server NEWID()

SQL Server NEWID function is a system function that  is used to generate a random unique value of type uniqueidentifier.

SYNTAX

NEWID()

A return type of NEWID function is uniqueidentifier.
Uniqueidentifier is a Microsoft SQL Server data type that is used to store Globally Unique Identifiers (GUIDs).
It can store 16 bytes of data.
Following is the valid format data value of type uniqueidentifier.

xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

Here x is a hexadecimal digit in the range 0-9 or a-f.

Lets look at an example of NEWID() in SQL Server.

Generate random unique id using NEWID Function

select newid() as uniqId

Using NewID function with variable

DECLARE @uniqid uniqueidentifier 
SET @uniqid = NEWID() 
Select @uniqId as UniqId

Variable declaration to store the value generated by NEWID function

You can store the value generated by NEWID function in variable, for this you need to declare a local variable of type uniqueidentifier, then assigned a value to it by using SET statement as shown below.

DECLARE @uniqid uniqueidentifier ; 
SET @uniqid = '97125ECE-EE01-4F23-89B7-5C425EC53BF7'; 
SELECT @uniqid as uniqId

Convert uniqueidentifier generated by NEWID function to Integer value

 
SELECT CAST(CAST(NEWID() AS VARBINARY) AS INT) AS UniqId

SELECT ABS(CAST(CAST(NEWID() AS VARBINARY) AS INT)) AS UniqId_positive

NEWID function with create table statement

CREATE TABLE dbo.Demo
(
DemoId uniqueidentifier NOT NULL DEFAULT NEWID(),
DemoName varchar(150)
)

INSERT INTO dbo.Demo
(DemoName) VALUES ('Demo On - Logistic Track Management')

Also Read

NEWSEQUENTIALID() Function