Hello,
I want to replace a string that contains these characters: < > "
I'm guessing that I can't simply enclose the string between ' and '
How do I do it?

For example, I'd like to run this query:
UPDATE xcart_products
SET fulldescr = REPLACE(fulldescr,'<param name="movie"','<param name="wmode" value="opaque"> <param name="movie"')

Is that the correct syntax?
TIA!

what happened when you tested it?

I didn't test then but I did now this way: I located an empty column in the db with the same properties as the column with live data, and added a row with the string: <param name="movie"
It worked, so I'm confident to run it on the live data. Thank you!
Actually, I will start doing this simple method to test queries and learn more quickly now! Thank you.

Actually, if you want to test a function, you don't have to create a table, just run the function directly without any column name in it:

select REPLACE('<param name="movie"','<param name="movie"','<param name="wmode" value="opaque"> <param name="movie"') as r