Convert SQL uniqueidentifier to varchar type

The niqueidentifier data type has 16 bytes, which is relatively larger than other 4-byte integers. This means that the index created using the uniqueidentifier key may be slower than the index implemented using the int key.
If the global uniqueness is not required, or a continuously incrementing key is required, you can use the IDENTITY attribute.

---? T Juwen Geovin Du
DECLARE @ myid uniqueidentifier
SET @ myid = NEWID ()
Select convert (char (255), @ myid) AS 'char ';
GO
--? T Juwen Geovin Du
Declare @ allstring char (255), @ AreaUid Uniqueidentifier
Set @ AreaUid = '37a1da94-4AC6-4ED0-B96F-BA3FE6AEACC8'
Set @ allstring = cast (@ AreaUid as char (255 ))
Select @ allstring
--? T Juwen Geovin Du
Declare @ allstring char (255), @ AreaUid Uniqueidentifier, @ s varchar (200)
Set @ AreaUid = '37a1da94-4AC6-4ED0-B96F-BA3FE6AEACC8'
Set @ allstring = CONVERT (char (255), @ AreaUid)
Set @ s = cast (@ allstring as varchar (200 ))
Select @ allstring, @ s
--? T Juwen Geovin Du
Declare @ allstring char (255), @ AreaUid Uniqueidentifier, @ s varchar (200)
Set @ AreaUid = '37a1da94-4AC6-4ED0-B96F-BA3FE6AEACC8'
Select @ s = CONVERT (varchar (200), cast (@ AreaUid as char (225 )))
Select @ s