Working Around SQL Replace Wildcards - mysql

Question

I know that I cannot use a wildcard in a MySQL replace query through phpMyAdmin. But, I need some kind of workaround. I'm very open to ideas. Here's the skinny:
I have about 2,000 pages in a MySQL database that need to have image URL's updated. Some are local, some are hotlinked. Each one is different, the URL lengths vary, the image on the page and the new image are unique per page id number, and each one occurs at a different spot in the page.
I basically need to do the following:
UPDATE pages SET body = replace(body, 'src=\"%\"', 'src=\"http://newdomain/newimage.jpg\"') WHERE id="{page_number}"
But I know that the 'src=\"%\"' component doesn't jive.
So I fall at the feet of your collective knowledge to come up with some way to take the src="%" and replace it with a set URL for a set page id number. Thanks in advance.

Answer 1

If there's only one image per page, a quick solution would be like this:
UPDATE pages
SET
body = CONCAT(
SUBSTRING_INDEX(body, 'src="', 1),
'src=\"http://newdomain/newimage.jpg\"',
SUBSTRING(
SUBSTRING_INDEX(body, 'src="', -1)
FROM LOCATE('"', SUBSTRING_INDEX(body, 'src="', -1))+1)
)
WHERE
id="{page_number}" AND
body NOT LIKE '%<img%<img%';
First SUBSTRING_INDEX extract the body part at the left of src=", the last two nested SUBSTRING_INDEX extracts the body part at the right of the first " next to src=".
Last check is a very dirty check to make sure that only one image is present in the string. It could fail under some circumstances, but it might help.

Answer 2

My suggestion would be to build a table with your replace strings that would look like this:
page_id replace
1 src="..."
Then you can update across a JOIN like this
UPDATE pages AS p
INNER JOIN replace AS r
ON p.page_id = r.page_id
SET p.body = REPLACE(p.body, CONCAT('src="', SUBSTRING_INDEX(SUBSTRING_INDEX(p.body, 'src="', -1), '"', 1), '"', r.replace);
This would replace the last occurrence anything of format src="..." with a new value in same format, so this would work for all records with a single src value.