Question

I’m designing a RESTful API and I’m trying to work out how I could represent a predicate with OR an operator when querying for a resource.

For example if I had a resource Foo with a property Name, how would you search for all Foo resources with a name matching “Name1” OR “Name2”?

This is straight forward when it’s an AND operator as I could do the following:
http://www.website.com/Foo?Name=Name1&Age=19

The other approach I’ve seen is to post the search in the body.

Answer 1

You will need to pick your own approach, but I can name few that seem to be pretty logical (although not without disadvantages):

Option 1.: Using | operator:

http://www.website.com/Foo?Name=Name1|Name2

Option 2.: Using modified query param to allow selection by one of the values from the set (list of possible comma-separated values):

http://www.website.com/Foo?Name_in=Name1,Name2

Option 3.: Using PHP-like notation to provide list instead of single string:

http://www.website.com/Foo?Name[]=Name1&Name[]=Name2

All of the above mentioned options have one huge advantage: they do not interfere with other query params.

But as I mentioned, pick your own approach and be consistent about it across your API.