SQL updating multiple cells with values from a subquery - sql

Question

The other day,I thought I found a very elegant way to update part of a set of cells. This is what I came up with :
Update mytable
Set ExternalLink = REPLACE (ExternalLink, R.UniqueID, R.ParentUniqueID)
From (
Select u.UniqueID, u.ParentUniqueID, RIGHT (mt.ExternalLink, 7) as EL
From uniqueidtable u
Join mytable mt
On EL = u.ParentUniqueID
Where mt.ExternalLink Like '%stringinurl%' ) R
I believe I got the idea from a stack question, but I can't find it in my history.
I can't seem to get more than one cell updated, even though the subquery returns several rows when tested alone. What's wrong with this and how can I tweak it to update multiple cells at a time?
Thank you for your help.

Answer 1

Okay, I came up with an answer. I'm not sure why a Table Expression did not work in this case, but here's what I came up with:
UPDATE mytable
SET ExternalLink = REPLACE(Ta.ExternalLink, T.ParentUniqueID, T.UniqueID)
FROM mytable Ta
JOIN UniqueIDtable
ON RIGHT(Ta.ExternalLink, 7) = T.ParentUniqueID
WHERE ExternalLink LIKE '%stringinurl%' AND ISNUMERIC(RIGHT(Ta.ExternalLink, 7)) = '1';
It seems I was just messing up the placement of the ID and parent ID in the replace. I also didn't count on the end of the URL string in the ExternalLink column to be anything but a numeric value, so that came up with some issues as well. It seems to be working for me now, so I've got that going for me.