Update SQL table with random value from other table

Question

On Microsoft SQL Server 2008, I have a table with Products:

Id | Name | DefaultImageId

And one with Images:

Id | ProductId |

Answer 1

Another possible solution

UPDATE
    Products
SET
    DefaultImageId =
    (
        SELECT TOP 1
            Id
        FROM
            Images
        ORDER BY
            NEWID(), Products.Id
    )