UNIQUEIDENTIFIER

一个 16 字节的 GUID / UUID。

DECLARE @GUID UNIQUEIDENTIFIER = NEWID(); 
SELECT @GUID -- 'E28B3BD9-9174-41A9-8508-899A78A33540'
DECLARE @bad_GUID_string VARCHAR(100) = 'E28B3BD9-9174-41A9-8508-899A78A33540_foobarbaz'
SELECT 
    @bad_GUID_string,   -- 'E28B3BD9-9174-41A9-8508-899A78A33540_foobarbaz'
    CONVERT(UNIQUEIDENTIFIER, @bad_GUID_string) -- 'E28B3BD9-9174-41A9-8508-899A78A33540'