I do not know how to do an "OR" sort of query like you are discussing, but am learning. Here's what I know about searching on non-Keyword fields (more on that later):
- You can search for a direct term, and by default, it will find any record that matches that index.
- You can turn on "Add wildcard to the search" for a field in a Search Dialog. This turns the search for that index into a "contains" logic instead of an exact match.
- You can use wildcard searching in the search value, such as "SearchTerm*", "*SearchTerm", and "*SearchTerm*". This gives you "starts with", "ends with" and "contains" functionality. A question mark can also be used in a wildcard search.
But I do not know how to do an "OR", but I very well could be missing something. You can do an "or" with URL Integration. In fact, you can do AND, OR, and NOT with URL Integration queries. You can also do AND and OR with Platform SDK searches, though I believe the search terms are then all AND or all OR -- they can't be a mix.
Now, one other way to make a field house multiple values (that can then be searched upon) is to make an index field be of the "Keyword" type. A Keyword field can house multiple values that you can search by. Though, this doesn't really help with your situation where you want to search for two things at once in the same field.
I do hope I am missing something here, and I am guessing I am. Because there are certain function keywords that can be used in queries, such as EMPTY() and NOTEMPTY().
That being said, I just checked the documentation, and found this:
You CAN use an "or" operator between two search terms. For example, I went to our Accounts Payable cabinet and tried this expression in vendor name to make sure I got all FedEx invoices:
"Federal Express" OR "Federal Express Corp."
and that worked.
So, the TL;DR version of this is that, yes, it can be done, just check the help page listed at the URL above.
NOTE: You MUST use uppercase keywords. You must use OR and AND and not "or" and "and". I was having trouble, and the case-sensitivity is what was tripping me up.