In SQL Server, the NEWID function generates an Universal Unique Identifier (UUID) of UNIQUEIDENTIFIER data type. In MySQL, you can use the UUID function that returns a UUID as a string.
SQL Server:
-- Generate UUID SELECT NEWID(); # 63579ACA-AE07-4290-9BAF-A72261B5FC44
MySQL:
-- Generate UUID SELECT UUID(); # 63579aca-ae07-4290-9baf-a72261b5fc44
For more information, see SQL Server to MySQL Migration.