T-SQL reference › uniqueidentifier
uniqueidentifier (GUID) in SQL Server
A uniqueidentifier is a 16-byte GUID. Systems use them when ids must be unique across machines. They are painful to type and make a clustered index jump around if you use NEWID().
Make one
SELECT NEWID() AS random_guid;At work, if the table already has an int identity, keep using that for joins. Join on the GUID only when that is the real key.
WHERE id = 'the-guid-without-quotes'
It is a literal. Quote it. And do not SELECT * and paste a 36-character id into Slack if a customer number exists.
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