Convert varchar to uniqueidentifier in SQL Server

Question

A table I have no control of the schema for, contains a column defined as varchar(50) which stores uniqueidentifiers in the format 'a89b1acd95016ae6b9c8aabb07da2010' (no hyphens)

I want to convert these to uniqueidentifiers in SQL for passing to a .Net Guid. However, the following query lines don't work for me:

select cast('a89b1acd95016ae6b9c8aabb07da2010' as uniqueidentifier)

select convert(uniqueidentifier, 'a89b1acd95016ae6b9c8aabb07da2010')

and result in:

Msg 8169, Level 16, State 2, Line 1

Conversion failed when converting from a character string to uniqueidentifier.

The same queries using a hyphenated uniqueidentifier work fine but the data is not stored in that format.

Is there another (efficient) way to convert these strings to uniqueidentifiers in SQL. -- I don't want to do it in the .Net code.

Answer 1

Try using the below code:

DECLARE @uuid VARCHAR(50)

SET @uuid = 'a89b1acd95016ae6b9c8aabb07da2010'

SELECT  CAST(

        SUBSTRING(@uuid, 1, 8) + '-' + SUBSTRING(@uuid, 9, 4) + '-' + SUBSTRING(@uuid, 13, 4) + '-' +

        SUBSTRING(@uuid, 17, 4) + '-' + SUBSTRING(@uuid, 21, 12)

        AS UNIQUEIDENTIFIER)

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