I\'ve looked for an answer to this, but all I can find is people asking how to search all columns of ALL tables in a database for a value. I just want to search all columns
I have no idea of the column types or data values you're searching for, but I'd guess you're trying to search for a substring among multiple text columns.
This is a job for Full-Text Search.
Don't waste time with LIKE '%' + @SearchStr + '%'
. You have to write a lot of complicated code to support it, and that solution won't perform well anyway.