SQL Server: converting UniqueIdentifier to string in a case statement

We have a log table that has a message column that sometimes has an exception stack trace. I have some criteria that determines if the message has this. We do not want to show these messages to the customer but instead have a message like:

> Internal Error Occured. Contact US
> with reference code
> xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

where xxx etc is a guid column in the table. I am writing stored proc like this:

declare @exceptionCriteria nvarchar(50)
select @exceptionCriteria = '%<enter criteria etc>%'

select LogDate,
case
when Message like @exceptionCriteria
then 'Internal Error Occured. Reference Code: ' + str(RequestID)
else Message
end
from UpdateQueue

`RequestID` is a Guid datatype in SQL Server and does not convert to string here. I've seen some code on how to convert a Guid to string, but it is multi-lined and I don't think it would work in a case statement. Any ideas?

Instead of `Str(RequestID)`, try `convert(varchar(38), RequestID)`

In my opinion, `uniqueidentifier` / GUID is neither a `varchar` nor an `nvarchar` but a `char(36)`. Therefore I use:

CAST(xyz AS char(36))

It is possible to use the convert function here, but 36 characters are enough to hold the unique identifier value:

convert(nvarchar(36), requestID) as requestID

Edit: yes, as noted in the comments, char, or nchar, or any function that can properly manipulate ASCII character tables would do the trick. Then, my excuse is that I usually work in a multilingual/multialphabet environment, and the rule is to go for nvarchar, always. That's my no-brainer way of doing things, sorry. And, if one of these days, some database software starts to generate unique identifier with non-ASCII elements, I will be ready.

I think I found the answer:

convert(nvarchar(36), RequestID)

Here's the link where I found this info:

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